Jeffco Aircraft/Industrial Epoxy

[Dave, 397]

I have just gotten a big mess of Jeffco Epoxy stuff from our accomodating composites wholesaler. As soon as I use up the last of my Fiberlay garbage (which as far as anyone can tell is private labelled system three) I'll let you know how it works.

One nice thing about this brand of material is that all of their resin products--barrier coats, surface coats, resins, etc.--take the same hardeners. Simple! Easy 4:1 by volume mix, so no hassle with pumps, either.

A lot of my thoughts on buying epoxy changed after I got to reading on a guy's website at www.epoxyproducts.com . He has a huge amount of information, although the website is very aggrevating to navigate...and he sells a lot of very heavy duty industrial LPU's, Epoxy products and other stuff...like FDA-approved barrier coat for potable water tanks, and a nuke-plant-certified barrier coat material (!). Amazing thing, the stuff is not so expensive as you'd think.

Anyhow, I look forward to giving a hands-on impression of the Jeffco stuff.

Dave

[Dave, 397]

In all, I am really happy with the Jeffco 3107-LV resin I got such a ton of. Only difficulty is in wetting out particularly heavy material as the epoxy is quite viscous...even more so than West System stuff. Heavier weight Biaxial in particular needs prewetting with a brush and a squeegee.

So, here's the question:

In past times of sheer desperation when an infusion-resin viscosity has been needed, I've succesfully thinned mixed epoxy with acetone. Improvised destructive testing programme long ago confirmed the the epoxy stays almighty strong, but it also seems to take quite a while to cure. Does anyone know of the "right" stuff with which one would reduce viscosity of the resin without stretching the full cure time out by a day or so?

Thanks,
Dave

[Dave, 397]

First, that's 1307-LV that I am using, not "3107LV" Oops.

I should also mention that Jeffco produces a broad line of epoxy products in many viscosities. 1307LV is "Structural Epoxy for Kit Aircraft". I chose it because it is a very high-solids, noncorrosive, low VOC material. Works great for most things but as I said it can be a bit of a challenge to get wetted thru in some materials.

Now for today's question #2:

Rollers...or rather, roller covers. I know, just know, that in bygone times I have used something besides the West System and similar 3.69-a-two-pack yellow foam roller covers for wetting/layup...something cheaper, that worked better. Darned if I can remember what, though, it was about 15 years ago. I go thru a good number of these things at this point, and I'd like to find something less costly that would do at least as good a job of wetting out if not hopefully a bit better, and also cost less. Despite what West say about their fine yellow foam covered phenolic cores, I find that they do not like being repeatedly rinsed/cleaned with acetone at all...I mean to say, the resin-impregnated *cores* of the roller covers do just fine...but the foam covering isn't so hot.

Anyone have a better mousetrap on this one?

Dave

[Tim]

Back in my brief sweatshop career laminating hulls, I remember using those brown nubby rollers, which are sold for spreading contact cement, to spread resin and begin the rollout process. I don't know what their price is, but they worked extremely well as resin rollers. Check the home centers in the Formica section, or near the contact cement. I bought some a year ago but don't have a clue what they cost.

Personally, I am continually underwhelmed by those yellow foam thingies. I rarely, if ever, use one. For smaller areas, I use plastic squeegees and brushes. Obviously, for doing large areas like decks or some such, some other means of spreading and saturation is required. I expect to check out the nubby brown ones when the time comes.

[Dave, 397]

Went looking for those nubby rollers but so far...even at the local commercial hardware outlet...I have not found them. Can you let me know if you find a good source?

Also...I am still looking for a way to thin the epoxy situation. Someone told me Isopropanol, and it seems like I have used alcohol to do the job before...but not on a boat, and not in quantities. Still looking for that answer. I suppose I could call up Jeffco, but I have yet to get the chance during the predictably short "how-can-I-help-you-you-poor moron" hours.

One last admission about me and the rollers...well, maybe two. Both heresy, but considering that they laid up my boat with something like a mop I don't feel as bad as I could otherwise.

Admission number one---
For larger pieces I don't wet out first. I slather the substrate with the roller, put the material in place, hit it with a de-airing roller to sort of tack it down and then wet it out/preliminarily de-air with the roller. THEN I hit it with the de-airing roller for the actual de-airing and finally squeegee the crap out of it to pull out the excess. I'm not too much of a finess-gifted fellow when it comes to laying 'glass.

Number two--
When I am dealing with things that do not NEED epoxy and which can be done before things which need epoxy in the same area are done (thus requiring anything going over/on top to be epoxy) I use polyester still. I dearly hate polyester, and the cloying stank of it in the shop really unhinges me. I mean the cloying stench that is there for days after the resin is fully cured, right? Yick. That much said, I like the fact that I can buy 5 gallons for about the price of one gallon of epoxy resin and associated hardner, and the fact that it can be thinned with acetone at will if needed. Here's my favorite reason to like it, though...family recipe, and all that...one of Dad's favorite tricks.
If you have the unfortunate task of laying up overhead, large spans overhead...or in odd angles...you can take polyester autobody filler, mix it real hot, thin it with catalysed poly resin to a consistentcy that will squeeze thru whatever you are laying up...and use little gobs of it to tack the material in place, holding as needed to wait for a secure tack. Now that the lovely 4-yard-long-by-bolt-width chunk of first-layer joy is in place, you can mix some slightly hot resin, thin as needed, and commit the heretical act of making a resin rich wet-out with the paint roller. De-air? You must be joking! The de-airing roller is only used for about 10 minutes to keep things where they need to be as the resin goes off. If you are organized and swift about it, it will be secure but still tacky enough to hold the next layer rather nicely while you go at IT. De-air or squeegee to you heart's content on that one and on subsequent layers. There you go...old family recipe. Crude, but effective...like the Pearson mop, or broom, or whatever the fellow has in hand and is dipping in a bucket in an old factory photo I have!

Best,
Dave

[Tim]

Also...I am still looking for a way to thin the epoxy situation

I believe you can thin epoxy with alcohol. I have yet to find a need for this in practical boat-use, and have therefore never done so. If thinner epoxy is needed, warming it is a better solution, I think.

Went looking for those nubby rollers but so far...even at the local commercial hardware outlet...I have not found them. Can you let me know if you find a good source?

I believe I found them most recently at Home Despot, in the aisle where the have the Formica. This was about a year ago. I just checked and I don't have one left here, so I can't even tell you the manufacturer, sadly. I do remember being excited about finding them at the time. I don't get over to the Despot much, but will look when I go since I'd like to have these in stock for when I glass the Daysailor decks.

[Tim]

Admission number one---
For larger pieces I don't wet out first. I slather the substrate with the roller, put the material in place, hit it with a de-airing roller to sort of tack it down and then wet it out/preliminarily de-air with the roller

That may be heresy in today's prepreg/impregnator/resin infusion high-tech mindset, but for normal hand-laminating methods there's nothing wrong with this. It's impractical to pre-wet large pieces beforehand. I do the pre-wet for all small pieces, but for large layups I wouldn't dream of it. All hand laminating, of course, gives the end result of a higher resin-fiber ratio (resin rich), but that's just the way it is. Today's top-end SCRIMP and similar boats have about half the resin in them that would be possible using hand layup. I doubt any of us will soon be using SCRIMP technology in our little boat repairs, though! hehe

[Dave, 397]

Yeah...if I could only have remembered to ask what KIND of mop when I spoke with Everett Pearson! Ha! I'd buy one! (hehe, as Tim would say!)

I wonder how much a vacuum-bagged E-glass Triton would (not) weigh...or a Vacuum-bagged E-glass Commander (given the lift in the A/C hull, that would REALLY fly!). Someone should find out someday, no?

Didn't the "Triton Factory" have a set of Triton molds?

Dave