SPRAYING AWLGRIP TOPCOAT
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KPAGE
SPRAYING AWLGRIP TOPCOAT
THIS WEEKEND I HAD PLANNED TO SPRAY AWLGRIP TOPCOAT. NOW I HAVE SOME SAFTEY CONCERNS. I WILL BE SPRAYING OUTSIDE (NO ENCLOSURE) AND HAVE PURCHASE THE RECOMENDED RESPORATOR (3M 5214). BUT AFTER READING SOME POST ON-LINE , IT SEEMS THAT YOU SHOULD NOT SRAY THIS PRODUCT WITH OUT A FRESH AIR SUIT. IS THIS CORRECT OR WOULD THAT ONLY BE FOR PROLONGED EXPOSURE AND ENCLOSED AREAS. ANY HELP WOULD BE APRECATED.
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The Good Goose
- Skilled Systems Installer
- Posts: 169
- Joined: Sat Apr 12, 2003 6:21 pm
I sprayed with a 3m respirator and the rectangular shaped charcoal filters when I did my mast and topsides. I did them inside. I also wore goggles and coveralls. I noticed no ill effects but I went in about two hours after spraying without a respirator and felt dizzy in about one minute. The stuff is really toxic definately wear a respirator whenever you are around it.
Just a tip if you get any bugs etc. probably best to leave them alone. I found if I tried to get rid of something in my paint ie. a small speck of lint it made a much bigger mess then the original problem. Go with several light coats if you spray to heavy the paint looks fine but when you return five minutes later it has sagged and ruined your paint job. I had to resand and recoat my cabin and cockpit due to this. remember easy does it you can always spray another coat after the last one flashes.
Good luck
Brock Richardson
Just a tip if you get any bugs etc. probably best to leave them alone. I found if I tried to get rid of something in my paint ie. a small speck of lint it made a much bigger mess then the original problem. Go with several light coats if you spray to heavy the paint looks fine but when you return five minutes later it has sagged and ruined your paint job. I had to resand and recoat my cabin and cockpit due to this. remember easy does it you can always spray another coat after the last one flashes.
Good luck
Brock Richardson
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Tim
- Shipwright Extraordinaire
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- Joined: Tue Apr 01, 2003 6:39 pm
- Boat Name: Glissando
- Boat Type: Pearson Triton
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- Contact:
From the Awlgrip website:
I know I'll feel a lot better myself using the supplied fresh air, however. I like my lungs; I find they come in handy nearly every day.
Right click here for the Awlgrip MSDS. Choose "Save target as" from the menu. Left-clicking may not work properly with this link.
I suppose in an outdoor space you could get by safely with a good cartridge respirator, but be sure it's the proper type. The atomized Awlgrip particles are very small and may penetrate some cartridges. It's always been my understanding that a supplied air suit was pretty essential, at least for indoor work. Obviously outdoors you have a ready supply of fresh air, but the fumes from the product are very strong nonetheless.Ventilation/Respiratory Protection: Use only with adequate ventilation. Maintain continuous flow of fresh air. Do not breathe vapors, spray mists, or sanding dusts. Wear appropriate, properly fitted respirator (NIOSH/MSHA approved) during and after application unless air monitoring demonstrates vapor and particulate levels are below applicable limits. Follow respirator manufacturer?s directions for respirator use. Engineering or administrative controls should be implemented to reduce exposure. Provide sufficient mechanical (general and/or local exhaust) ventilation to maintain exposure below TLV?s (Threshold Limit Values).
I know I'll feel a lot better myself using the supplied fresh air, however. I like my lungs; I find they come in handy nearly every day.
Right click here for the Awlgrip MSDS. Choose "Save target as" from the menu. Left-clicking may not work properly with this link.
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KPAGE
Sorry guys I believe my question was worded wrong. Let see if I can get it right this time. I was told that a fresh air resp. was intended for use in inclosed areas were the pump could be away (outside) from the fumes. (A local rental shop told me this). And the resp. I purchased is NISHO approved resp. Will it be safe to use.? Is the information about the fresh air resp. correct?
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Tim
- Shipwright Extraordinaire
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- Joined: Tue Apr 01, 2003 6:39 pm
- Boat Name: Glissando
- Boat Type: Pearson Triton
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- Contact:
The intake for any supplied air system must, of course, be located in a region of clean, fresh air and away from the spray or paint fumes. These supplied air compressors come equipped with the intake located directly on the compressor. When working indoors, you can either locate the whole compressor outside in the fresh air, or, even better, get an extended intake hose that allows you to leave the compressor alone, but to still get fresh air from outside. The logistics of moving the compressor outside can be tough, since you have to lead the air hose inside, etc. This can be a pain. The remote location allowed by using the intake extension is the way to go.
I described my supplied air system, including the extended intake hose, in this thread here on the forum: http://www.triton381.com/forum/viewtopic.php?t=317 (scroll down a bit). Check it out to see what I'm talking about.
If using a supplied air system outside, the same rules would apply: the compressor intake, or extended hose intake (if equipped), would have to be located somewhere a good distance away from the work zone to ensure clean, fresh air supply that was not tainted by the work going on. To do this effectively, you would need either additional lengths of air supply hose (to locate the compressor far away), or a length of the air intake extention hose that would allow the intake to be located some distance away, and preferably upwind.
Proper setup is the key, regardless of whether the machine is being used inside or outside.
I described my supplied air system, including the extended intake hose, in this thread here on the forum: http://www.triton381.com/forum/viewtopic.php?t=317 (scroll down a bit). Check it out to see what I'm talking about.
If using a supplied air system outside, the same rules would apply: the compressor intake, or extended hose intake (if equipped), would have to be located somewhere a good distance away from the work zone to ensure clean, fresh air supply that was not tainted by the work going on. To do this effectively, you would need either additional lengths of air supply hose (to locate the compressor far away), or a length of the air intake extention hose that would allow the intake to be located some distance away, and preferably upwind.
Proper setup is the key, regardless of whether the machine is being used inside or outside.
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Dave, 397
Protective gear
Besides the obvious inhalation hazard, the real issue of protection is the skin and other areas of potential contamination (ears, for example). The ears are in fact a very sensitive area that you DO NOT want to have get catalyzed urethanes inside of.
If you are not wearing the respirator in question in a high-production environment on a daily basis, a supplied air system is not an absolute requisite. It pays to remember that MSDS info is written from a standpoint of extreme occupational exposure in most cases, often in fact by taking the typical occupational exposure and then MULTIPLYING it! There are MSDS for common household cleaning products that would scare a guy to death.
Protection of the skin is the main issue here, as is protection of the eyes. I know people who have periodically sprayed catalysed urethanes on aircraft and cars on a hobby basis in settings without positive evacuation (i.e., not in a spray booth) wearing only a half-mask respirator and safety glasses for many years, with no ill effects. As a compromise to the fresh-air system, you may find that a good full-mask respirator will make you very happy...provides protection for eyes and face as well as giving you a good tool to use in other high-irritant settings like grinding fibergalss in a confined area like a cockpit locker.
The main protective gear to insure one has...can be gotten at any autobody supply house. "Moon Suit", gauntleted nitrile gloves ("Green Gloves") and nitrile boots. You can save some money here and come out the same by wearing the pair of black rubber knee boots that you probably already own and pulling a pair of tyvek shoe covers over them to prevent marring the decks. While it is not OSHA-required to do so for painting, extra protection is afforded by taping the boots, gloves and mask off to the hooded suit. No need to get TOO nutty here, you are not cleaning up pathogens from overhead, right?
BTW, the "moon suit" is a blessed innovation in recent years, as previously the recommended item was the same plasticed, heavy-tyvek suit that IS used for pathogens...very, very hot to wear. The moon suit is a lighter material that almost looks like spinnaker cloth and is both impermeable by overspray and much cooler to wear. Buy your suit way too big so as to have that much cooler an experience. Apparently it was decided at one point that Tyvek suits are somewhat permeable by some solvents found in paint--particularly urethane paint--overspray. Remember though that this is in reference to full-time occupational exposure. Tyveks are cheaper, moon suits are cooler...take your pick. Spraying outdoors, you will not be catching a whole lot of overspray anyhow.
As to the respirator...a good pair of prefilter pads will extend your cartridge life and help insure the carts do their job. While not true with all hazards, with paint...if you are not smelling it, if you are not tasting it...you are not getting it.
Whether you are purchasing a supplied-air mask or simply a full-mask respirator, I would recommend that you do so from an industrial safety house if there is one reasonably nearby. Most safety suppliers carry more than one brand, and I have found that some people may not find a good fit in any given brand regardless of size...but will find an excellent fit in another. The staff at these places are well-experienced in fitting respirators to people, so they will be of great assistance to you in insuring the best fit. As an added bonus, the prices are often much better than at the industrial hardware supplier or the autobody store...don't ask me why.
Just last week I had to help a friend find a full-mask unit for a hazmat job that we did over this last weekend...we went thru three different brands before we found one that was both a good fit and comfortable enough for extended wear.
Again, you are only painting one boat here...while it is not a friendly substance to the body and reasonable protective measures are certainly prudent, it pays to remember that this is only paint and solvents...not Ebola.
Best,
Dave
If you are not wearing the respirator in question in a high-production environment on a daily basis, a supplied air system is not an absolute requisite. It pays to remember that MSDS info is written from a standpoint of extreme occupational exposure in most cases, often in fact by taking the typical occupational exposure and then MULTIPLYING it! There are MSDS for common household cleaning products that would scare a guy to death.
Protection of the skin is the main issue here, as is protection of the eyes. I know people who have periodically sprayed catalysed urethanes on aircraft and cars on a hobby basis in settings without positive evacuation (i.e., not in a spray booth) wearing only a half-mask respirator and safety glasses for many years, with no ill effects. As a compromise to the fresh-air system, you may find that a good full-mask respirator will make you very happy...provides protection for eyes and face as well as giving you a good tool to use in other high-irritant settings like grinding fibergalss in a confined area like a cockpit locker.
The main protective gear to insure one has...can be gotten at any autobody supply house. "Moon Suit", gauntleted nitrile gloves ("Green Gloves") and nitrile boots. You can save some money here and come out the same by wearing the pair of black rubber knee boots that you probably already own and pulling a pair of tyvek shoe covers over them to prevent marring the decks. While it is not OSHA-required to do so for painting, extra protection is afforded by taping the boots, gloves and mask off to the hooded suit. No need to get TOO nutty here, you are not cleaning up pathogens from overhead, right?
BTW, the "moon suit" is a blessed innovation in recent years, as previously the recommended item was the same plasticed, heavy-tyvek suit that IS used for pathogens...very, very hot to wear. The moon suit is a lighter material that almost looks like spinnaker cloth and is both impermeable by overspray and much cooler to wear. Buy your suit way too big so as to have that much cooler an experience. Apparently it was decided at one point that Tyvek suits are somewhat permeable by some solvents found in paint--particularly urethane paint--overspray. Remember though that this is in reference to full-time occupational exposure. Tyveks are cheaper, moon suits are cooler...take your pick. Spraying outdoors, you will not be catching a whole lot of overspray anyhow.
As to the respirator...a good pair of prefilter pads will extend your cartridge life and help insure the carts do their job. While not true with all hazards, with paint...if you are not smelling it, if you are not tasting it...you are not getting it.
Whether you are purchasing a supplied-air mask or simply a full-mask respirator, I would recommend that you do so from an industrial safety house if there is one reasonably nearby. Most safety suppliers carry more than one brand, and I have found that some people may not find a good fit in any given brand regardless of size...but will find an excellent fit in another. The staff at these places are well-experienced in fitting respirators to people, so they will be of great assistance to you in insuring the best fit. As an added bonus, the prices are often much better than at the industrial hardware supplier or the autobody store...don't ask me why.
Just last week I had to help a friend find a full-mask unit for a hazmat job that we did over this last weekend...we went thru three different brands before we found one that was both a good fit and comfortable enough for extended wear.
Again, you are only painting one boat here...while it is not a friendly substance to the body and reasonable protective measures are certainly prudent, it pays to remember that this is only paint and solvents...not Ebola.
Best,
Dave
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KPAGE
Thanks again guys for some great advise. Used the suit and it worked great , with the exception of the barb-b-que, i'll save that story for another time.
Painted 3 coats total. The first coat went on great, no runs and smooth, the second coat was the same, here comes the question. After spraying the third and final coat a run developed on the gunnel ( top edge) it did not show up for almost a hour. I only have about 3oz. total of paint. What is the best way to fix the run. Can I wet sand just that area and touch-up spray or will this show over spray.
I cant afford to buy any more awl-grip and I do not want to make it look worst than it does now.
Any ideas,
Kenny
Painted 3 coats total. The first coat went on great, no runs and smooth, the second coat was the same, here comes the question. After spraying the third and final coat a run developed on the gunnel ( top edge) it did not show up for almost a hour. I only have about 3oz. total of paint. What is the best way to fix the run. Can I wet sand just that area and touch-up spray or will this show over spray.
I cant afford to buy any more awl-grip and I do not want to make it look worst than it does now.
Any ideas,
Kenny
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KPAGE
Ok, Dave remember this only funny if your not the one wearing the mask.
Friday was my first day spraying awlgrip and first time using a fresh air hood. First thing is I was at my uncles house because he has a large yard, enough to spray the boat. As you drive in you pass the house then a small yard, his garage and then a large lot were the boat is. I set the air pump close to the garage and ran the intake hose toward the house.
now everything is set, wiped the boat down with awlprep, (no fumes this is nice) mixed paint, began to spray. The hood takes a little getting use to, but things are going good.
When all of a sudden a little smell in the hood what could this be? over spray going against the wind? (now remember i'm a little nervous with this paint) trying to comfort my self a say there no way the fumes can be reaching that far. when all of a sudden the hood completely fills with smoke. I drop the gun, pull off the mask and take off running. The only this I can think of was reading the caution label on the can DO NOT INHALE!!!!! I get to the house my eyes still watering from the smoke I look up, only to see the BBQ pit sitting less than a foot away from the intake.
Now that the world nows my humilation. Can I get a little help with the paint question.
Friday was my first day spraying awlgrip and first time using a fresh air hood. First thing is I was at my uncles house because he has a large yard, enough to spray the boat. As you drive in you pass the house then a small yard, his garage and then a large lot were the boat is. I set the air pump close to the garage and ran the intake hose toward the house.
now everything is set, wiped the boat down with awlprep, (no fumes this is nice) mixed paint, began to spray. The hood takes a little getting use to, but things are going good.
When all of a sudden a little smell in the hood what could this be? over spray going against the wind? (now remember i'm a little nervous with this paint) trying to comfort my self a say there no way the fumes can be reaching that far. when all of a sudden the hood completely fills with smoke. I drop the gun, pull off the mask and take off running. The only this I can think of was reading the caution label on the can DO NOT INHALE!!!!! I get to the house my eyes still watering from the smoke I look up, only to see the BBQ pit sitting less than a foot away from the intake.
Now that the world nows my humilation. Can I get a little help with the paint question.
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Dave, 397
Hey...there's always a witness, you know? Since you didn't have one right ther right then, you have now made all things be in balance, hehe! Beside, it was funny. 'Least you didn't set yourself afire...or earn the name "Breakwater Dave".
I have not had to work with AwlGrip, so I can't readily address the particular product. Tim had to do some retouching on GLISSANDO, and it's on the 381 website.
I have worked with other catalyzed urethanes, though, and I'll give my general experience and thoughts. First, the sooner you work this run off, the better. Cat. Urethanes I have worked with seem to harden up more fully in the first week after application, so you will do well to get right on it. If it were me, I'd take a small block of hardwood (appx. 2 x3", 2-1/2 x 3-1/2, or similar) and make sure it was dead flat (!) and than round the corners and chamfer the edges (!!) of the now-dead-flat surface. Then I would suggest wet-sanding with 600 grit paper wrapped snugly around the block. The big trick here is to work slowly and carefully so that the block and paper ride only on the bump and do not rock at all (landing on and sanding into the surrounding area, making new low spots in the process that render the high spot that much higher!). If the 600 is not cutting at all, go to 400.
If possible, go to the autobody supply house and get 800 grit paper instead of the 6. It actually cuts just as well and is much more uniform...3M (and everyone else, reportedly) make all of their silicon-carbide products up to and including 600 in a common area, so it is not uncommon at all to get some 320 rocks in your 600 paper. You can't see or feel them, but they sure show up on the finish! The grits 800 and above are made in some sort of isolation to prevent this.
Work most of the bump off with your coarsest grit, then go finer. You can buy--and will want to--wet/dry paper in 1000, 1200, 1500 and 2000 grits. For any finish sanding, the trick is to take off just enough with each grit that by the time you are through with the finest and have removed all of the previous grit's scratches, the bump has JUST left. You can then work by hand with Meguiar #2, and finish with a drill-mounted foam buff pad and Meguiar #9. Again assuming that AwlGrip works like any other Catalysed Urethane, and assuming you have done a good and careful job, you should have a nice shiny matching surface without applying additional paint. If it doesn't quite work out like you wanted, use a Jamb Gun ("detail gun"--a 25.00 China Special will do fine here) and overspray the repaired area, then buff out and blend into the surrounding area as soon as possible. If there is some "halo"---and there may well be---you can try to blend it out a bit by wetsanding with 1500 and 2000 and then buffing again.
One word on wetsanding, too---Keep the Paper (and the surface) flushed clean. If you cannot clearly see the detail area you are tying to work, you cannot work it accurately...and, just as importantly, the slurry built up on the paper of removed paint and shed grit will scratch the tar out of the work in ways you do not like.
Hopefully some of this helps, and hopefully someone with experience dealing with AwlGrip specifically will jump in and help out, most importantly correcting anything I may have suggested that does not work out with the specific product.
All the same, AG is similar enough to the old 2-part Deltron and the Fleetstar-type products (all of these, including AwlGrip, originated as aircraft paints) that I would strees the need to get on this ASAP for best result...same goes for any buffing-out or colorsanding (wetsanding to remove orange peel or other defects)-and-buffing out you may need to do.
(Sort Of) Lastly...if you have any small "zits" or bugs that you want to remove, there is an inexpensive little tool that the Autobody house can sell you called a "Speck-Out Nib File" that will make short and clean work of the problem. You simply work the nib out with light and careful (so as not to rock the tool and mar with the edge or corner) strokes, then colorsand (wetsand) with the finest grits of paper that will do the job and then buff.
It's worth noting that the finest grits of paper come in tiny sheets and get a bit spendy as sandpaper goes. They work best if you soak them in clean water for an hour or two before use, and as long as they are not worn out you can put them somewhere clean (keep the different grits carefully segregated!), let them dry out, and save them for re-use. In my instrument shop we used to stick them face-down on little bits of tempered masonite, then use those bulldog clips the lawyers use to hold mondo stacks of paper together to clamp them flat with pieces of drilled plexiglas...or you can find somebody who smokes Nat Sherman's cigs and get those nifty little boxes from them and just toss 'em in. It is also very helpful to write the grit on the back of each pice with a sharpie pen to help keep them straight, as it is hard to feel the difference between these very fine grits with your finger.
Hope that some of this helps.
Best,
Dave
I have not had to work with AwlGrip, so I can't readily address the particular product. Tim had to do some retouching on GLISSANDO, and it's on the 381 website.
I have worked with other catalyzed urethanes, though, and I'll give my general experience and thoughts. First, the sooner you work this run off, the better. Cat. Urethanes I have worked with seem to harden up more fully in the first week after application, so you will do well to get right on it. If it were me, I'd take a small block of hardwood (appx. 2 x3", 2-1/2 x 3-1/2, or similar) and make sure it was dead flat (!) and than round the corners and chamfer the edges (!!) of the now-dead-flat surface. Then I would suggest wet-sanding with 600 grit paper wrapped snugly around the block. The big trick here is to work slowly and carefully so that the block and paper ride only on the bump and do not rock at all (landing on and sanding into the surrounding area, making new low spots in the process that render the high spot that much higher!). If the 600 is not cutting at all, go to 400.
If possible, go to the autobody supply house and get 800 grit paper instead of the 6. It actually cuts just as well and is much more uniform...3M (and everyone else, reportedly) make all of their silicon-carbide products up to and including 600 in a common area, so it is not uncommon at all to get some 320 rocks in your 600 paper. You can't see or feel them, but they sure show up on the finish! The grits 800 and above are made in some sort of isolation to prevent this.
Work most of the bump off with your coarsest grit, then go finer. You can buy--and will want to--wet/dry paper in 1000, 1200, 1500 and 2000 grits. For any finish sanding, the trick is to take off just enough with each grit that by the time you are through with the finest and have removed all of the previous grit's scratches, the bump has JUST left. You can then work by hand with Meguiar #2, and finish with a drill-mounted foam buff pad and Meguiar #9. Again assuming that AwlGrip works like any other Catalysed Urethane, and assuming you have done a good and careful job, you should have a nice shiny matching surface without applying additional paint. If it doesn't quite work out like you wanted, use a Jamb Gun ("detail gun"--a 25.00 China Special will do fine here) and overspray the repaired area, then buff out and blend into the surrounding area as soon as possible. If there is some "halo"---and there may well be---you can try to blend it out a bit by wetsanding with 1500 and 2000 and then buffing again.
One word on wetsanding, too---Keep the Paper (and the surface) flushed clean. If you cannot clearly see the detail area you are tying to work, you cannot work it accurately...and, just as importantly, the slurry built up on the paper of removed paint and shed grit will scratch the tar out of the work in ways you do not like.
Hopefully some of this helps, and hopefully someone with experience dealing with AwlGrip specifically will jump in and help out, most importantly correcting anything I may have suggested that does not work out with the specific product.
All the same, AG is similar enough to the old 2-part Deltron and the Fleetstar-type products (all of these, including AwlGrip, originated as aircraft paints) that I would strees the need to get on this ASAP for best result...same goes for any buffing-out or colorsanding (wetsanding to remove orange peel or other defects)-and-buffing out you may need to do.
(Sort Of) Lastly...if you have any small "zits" or bugs that you want to remove, there is an inexpensive little tool that the Autobody house can sell you called a "Speck-Out Nib File" that will make short and clean work of the problem. You simply work the nib out with light and careful (so as not to rock the tool and mar with the edge or corner) strokes, then colorsand (wetsand) with the finest grits of paper that will do the job and then buff.
It's worth noting that the finest grits of paper come in tiny sheets and get a bit spendy as sandpaper goes. They work best if you soak them in clean water for an hour or two before use, and as long as they are not worn out you can put them somewhere clean (keep the different grits carefully segregated!), let them dry out, and save them for re-use. In my instrument shop we used to stick them face-down on little bits of tempered masonite, then use those bulldog clips the lawyers use to hold mondo stacks of paper together to clamp them flat with pieces of drilled plexiglas...or you can find somebody who smokes Nat Sherman's cigs and get those nifty little boxes from them and just toss 'em in. It is also very helpful to write the grit on the back of each pice with a sharpie pen to help keep them straight, as it is hard to feel the difference between these very fine grits with your finger.
Hope that some of this helps.
Best,
Dave
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Tim
- Shipwright Extraordinaire
- Posts: 5708
- Joined: Tue Apr 01, 2003 6:39 pm
- Boat Name: Glissando
- Boat Type: Pearson Triton
- Location: Whitefield, ME
- Contact:
I'd say Dave's suggestions are as good as any I might have come up with. I will further stress the main point: get on the repair immediately. Awlgrip does have a well-documented cure schedule, and after a week or so it's well into stage 2 and on its way to the rock-hard and nearly unretouchable stage 3.
Good luck with the repair. Typically, it's hard to repair Awlgrip without it showing, especially if you have dark hull color. But it can be done with relative, if not perfect, success.
Good luck with the repair. Typically, it's hard to repair Awlgrip without it showing, especially if you have dark hull color. But it can be done with relative, if not perfect, success.
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Dave, 397
I failed to mention one important detail---
While you are sanding off the bulk of the sag, you will do best to work in a small, circular motion, working your way evenly along the length of the material you want to knock off. Try and establish a level surface that is parallel to the actual surface you are sanding down towards so that when you meet that surface you will do so all at once.
At some point in the process you will start kissing the surface that you are trying to level to, and by the end you will be sanding on it to some degree. When you arrive at this point, you may do best to finish out by sanding with a linear motion. Seems like the hand rubbing (which will be in little overlapping circles going back and forth along the repair area) and the rotary buffing (also circular, of course) go better taking out linear sanding scratcheds than overlapping circular ones, IMO.
Also, on this whole sanding bit...patience and a calm perspective are very useful tools. While you are sanding on this, good control is essential, and part of that is to not press on the sanding block any more than is necessary to get the paper to cut. Bearing down too much will invariably lead to problems.
Seems like I always have to toss in an example someplace, so here we go--
I had an old guy that did finish and inlay work in my shop...incredibly talented, a real artist. Did the whole perfect-scale-model-ship thing, built custom RC planes for people by using proportional dividers and photos of the actual aircraft, lots of stuff. In his spare time he was a nationally-renowned scrimshaw artist---he did exquisite stuff. He could also do some really incredible finish repairs on very difficult finishes (pre WW I stuff is particularly difficult due to the type of finish media involved ---for example, hehe). One of the big tricks to this was his accuracy at riding just on top of, only on top of, the repair he was working down. The other was an incredibly fine feel. As you will soon find out, even very fine paper, even when you are wetsanding...it makes a noise. I used to watch Scott working on some of these things and think..."Sheesh! He's taking forever on this teeny bump! What's he doing? Is he even CUTTING on that?!?"...because I couldn't hear anything at all, he'd go to so light a touch towards the end. Don't think you need to be quite that gentle, especially on the finish you are working with, but I thought I'd mention it as an example of what sort of methodology gets what sort of result.
I also mentioned chamfering off the edges of the block and rounding the corners. This is essential and must not be neglected as otherwise it is nearly impossible, no matter how skilled a guy is, to avoid dragging the paper on areas you do not want to and digging a hole around the spot you are trying to bring flush...the end result is usually an almighty thin--if not bald--spot. It's also essential to use a hard block. Maple is good, as is marine ply with the edges sealed (thin superglue penetrates great and is easy to smooth out!). Regular autobody-type hand blocks, even the hardest of the hard rubber ones...will flex enough to ruin your work.
This is really not that hard or complicated once you get into it, and I hope I am not making it sound too horrible or whatnot. Just thinking of the common pitfalls and easy mistakes to make, so that you don't have to learn the hard way. Worry not, you'll get it done just fine!
Good Luck, and happy sanding!
Dave
While you are sanding off the bulk of the sag, you will do best to work in a small, circular motion, working your way evenly along the length of the material you want to knock off. Try and establish a level surface that is parallel to the actual surface you are sanding down towards so that when you meet that surface you will do so all at once.
At some point in the process you will start kissing the surface that you are trying to level to, and by the end you will be sanding on it to some degree. When you arrive at this point, you may do best to finish out by sanding with a linear motion. Seems like the hand rubbing (which will be in little overlapping circles going back and forth along the repair area) and the rotary buffing (also circular, of course) go better taking out linear sanding scratcheds than overlapping circular ones, IMO.
Also, on this whole sanding bit...patience and a calm perspective are very useful tools. While you are sanding on this, good control is essential, and part of that is to not press on the sanding block any more than is necessary to get the paper to cut. Bearing down too much will invariably lead to problems.
Seems like I always have to toss in an example someplace, so here we go--
I had an old guy that did finish and inlay work in my shop...incredibly talented, a real artist. Did the whole perfect-scale-model-ship thing, built custom RC planes for people by using proportional dividers and photos of the actual aircraft, lots of stuff. In his spare time he was a nationally-renowned scrimshaw artist---he did exquisite stuff. He could also do some really incredible finish repairs on very difficult finishes (pre WW I stuff is particularly difficult due to the type of finish media involved ---for example, hehe). One of the big tricks to this was his accuracy at riding just on top of, only on top of, the repair he was working down. The other was an incredibly fine feel. As you will soon find out, even very fine paper, even when you are wetsanding...it makes a noise. I used to watch Scott working on some of these things and think..."Sheesh! He's taking forever on this teeny bump! What's he doing? Is he even CUTTING on that?!?"...because I couldn't hear anything at all, he'd go to so light a touch towards the end. Don't think you need to be quite that gentle, especially on the finish you are working with, but I thought I'd mention it as an example of what sort of methodology gets what sort of result.
I also mentioned chamfering off the edges of the block and rounding the corners. This is essential and must not be neglected as otherwise it is nearly impossible, no matter how skilled a guy is, to avoid dragging the paper on areas you do not want to and digging a hole around the spot you are trying to bring flush...the end result is usually an almighty thin--if not bald--spot. It's also essential to use a hard block. Maple is good, as is marine ply with the edges sealed (thin superglue penetrates great and is easy to smooth out!). Regular autobody-type hand blocks, even the hardest of the hard rubber ones...will flex enough to ruin your work.
This is really not that hard or complicated once you get into it, and I hope I am not making it sound too horrible or whatnot. Just thinking of the common pitfalls and easy mistakes to make, so that you don't have to learn the hard way. Worry not, you'll get it done just fine!
Good Luck, and happy sanding!
Dave