repair questions

[jeffwagnpete]

Instead of tearing out a bulkhead like I did before. Could just cut out the rotted section of the bulkhead and replace it with new plywood? Then use cloth and epoxy to put over the new section? Also, I just finished making my shelter about 3 weeks ago, so now I was able to remove every bit of hardware from my boat. It's completely stripped now and nice and dry. Do I need to drill out all the old holes half deep and refill with epoxy. I see Tim does this to make sure there are no voids around the old hardware holes and then he epoxy's this. Also, I am going to need to replace alot of the balsa core on the deck. Do I just cut the top skin layer off and save and chip away the old stuff inside? Also, does corecell work good on replacing parts of the skin from the deck?
Has anyone ever used epoxy in the winter time, if so, what are some helpful hints such as heat and does its really cure good under heat lamps?

Jeff

[Rachel]

Hi Jeff,

I'm going to say that you could probably find some good reading and information from past posts on the forum, by using the search function.

My worry by writing this is that you'll feel we don't want to answer your questions - and I hope you don't take it that way. It's just that there's been some great discussion about this stuff in the past, and it seems a shame to "waste" it.

I think we've had a number of threads on bulkhead replacement, overdrilling and filling fastener holes, deck re-coring, and using epoxy in cold weather. Many forumites have contributed and so there are a number of perspectives and probably some questions asked and answered that you won't know you had until you read them :)

Edited to add:

Here are a few threads that I was thinking of:

Deck re-coring:
Recore link 1

Recore link 2

Recore link 3

Recore link 4

Bulkheads:
Bulkhead link 1

Bulkhead link 2

Bulkhead link 3

Bulkhead link 4

Bulkhead link 5

Overdrilling and filling holes:
Drill and fill link 1

Drill and fill link 2

Drill and fill link 3

Hope this helps. Before you know it the sun will be rising and it will be time to go to work tomorrow ;)

Rachel

[jeffwagnpete]

Ok, thank you Rachel! I will read these and I'm sure I will get some helpful info from these.

[Rachel]

By the way, at least in my opinion, it's perfectly acceptable (and even desirable) to add something new onto the ends of the older threads, if you come up with a question that fits in. (If this isn't the general consensus, please pipe in!)

Some folks are even known for being skilled in the art of "the dredge." :<)

R.

[Hirilondë]

Jeff,
There are definitely ways to repair a plywood bulkhead that do not require tearing it out. The method you describe seems like it might work just fine. Depending on the bulkhead, whether it is structural or not, how much material needs to be replaced, and other factors like how you join the patch to the existing, you may not even need the glass reinforcement.

Some folks are even known for being skilled in the art of "the dredge." :<)

Rachel the Dredge, I like it!!!

[Rachel]

Rachel the Dredge, I like it!!!

Ah, but I'm just a disciple. Aren't Britton and Figment the true masters? :^)

[Figment]

and don't you forget it, missy.

[jeffwagnpete]

I forgot to mention that when I was taking off some hardware, I was poking around the holes and doing some investigating around the holes, I was chipping away the rotted out core and the bottom skin was tearing apart as well, so now the hole was getting bigger. HUH, I am eager to start this process but nervous to do, Theres alot of skill sawing out the outer skin and replacing, I guess I am just scared to do this because this is such foreign territory I am entering now. I really need a camera. I start this process on friday. Oh, what kind of drill bit would I use to drill out the old hardware holes? A counter sinker bit or a spade bit? Or what have you guys used?

[Rachel]

When I overdrilled the holes for hardware fasteners, I used a sort of two-part drill bit.

What I did was mate a regular twist drill bit that was the basic "oversized" size that I wanted for the fasteners (can't remember exactly what it was; maybe 5/16" or so) with a hole saw of about 1" (or maybe 1-1/4"), so they were one drilling unit.

I then drilled from inside the boat, up through the deck. The twist bit went all the way through, but with the hole saw part I only went through the bottom skin and the core (and not through the top deck skin).

This gave me a nice wide core sample and also the chance to reef out even more core if it looked damp around the edges. Then when I filled with thickened epoxy the whole thing was filled in, after which I redrilled through the new annulus with a twist bit that was properly sized for the to-be-installed hardware fastener.

It sounds like a lot of bother, but once I had the bits set up it was pretty quick.

When I went back to fill the holes I taped over the below-decks side with clear packaging tape. It let me see that the epoxy was filling everything up with no air pockets, and it just peeled right off afterward. I taped around the holes on deck, let the new epoxy hump up a bit, and then trimmed it off when it was in the "green" stage so that it was flush.

One issue I did have was with air getting in along with the epoxy and then later the fill would "slump" and I'd have to fill again. I solved that by using a syringe and filling from below (like an outboard motor lower unit). I'd tape over the hole with the clear packing tape, then poke the syringe into the tape, fill the hole, and then slap another piece of tape on as I withdrew the syringe.

Not that one can't fill from above just fine - I just happened to be sick of having to go back and "top off" the holes.

Some slight defects in the bottom skin around your hardware fastener locations might not be too much of an issue if you are using (or adding) properly large backing plates for your deck hardware.

And yes, a camera is a necessary tool! We must see photos! :D

Rachel

[okawbow]

I had to drill oversize holes from the deck, when I re-fastened my stanchions. There just isn't room to drill from below. I used a 3/4" spade bit, and stopped short of drilling through the bottom skin. I then made a cutting tool from a 1/4" allen key, to "rout" out the core inside the holes, to about 1 1/2" diameter. I taped the bolt hole on the inside, then poured in epoxy that was thickened only to the point where it would still self level. Like Rachel says; mask around the hole on deck, and over fill slightly to allow for shrinkage.

[mitiempo]

Ideally you don't overdrill either the top or bottom skin in my opinion. I use a Dremel bit (#654) in a flex drive that fits in a 1/4" hole and rout out the core around the hole without making the holes in the skins any larger than necessary. See this link for details with pictures from Maine sail. http://www.pbase.com/mainecruising/sealing_the_deck
Brian

[Rachel]

Brian,

I see the philosophy behind what you're saying, and your preference for keeping both skins intact, but I think that removing some of the bottom skin does not hurt in the typical scenario where you are adding a backing plate to the underside. In my opinion, that plate should spread the loads and avert problems far more than just a bottom skin would, and by taking a bit of the bottom skin away you can access more of the core more easily.

That's not to say that one must drill a larger hole in the bottom skin, but I don't believe that it is always important to avoid, say, having a 1" diameter hole in the bottom skin vs. a 3/16" hole.

Rachel

[mitiempo]

Rachel, I see your point. My method (really Maine sail's) would be best if you have poor access below to drill.
Brian