wow - this is work. Bulkhead, port delamination and sanding, sanding, sanding
I spent another 4 hours tonight sanding down fiberglass and removing any delaminated glass and it doesn't seem to be looking any better. The berth is out, the bulkhead has been removed and the problem we thought was big is a little bigger.
We're not pros here. We're just trying to figure this one out.
After all of the sanding, it looks like the stand the boat was on has caused a lot more damage than we thought - it's delaminated all the way through and has actually made a nice square imprint on the damaged area. It looks like we'll be at this for a while yet.
How cold can you work with fiberglass? We want to get this done this season, but the fix keeps getting bigger. Any tips & encouragement are welcome.
At least Jude has cut a new bulkhead and it looks pretty excellent.
Jude's got a real talent for wood.
Looks pretty good so far.
What stage are we looking at?
On another thread there some detailed opinions.
Here's a short recap, hopefully.
Use only 100% solids epoxy, Low VOC, NO solvents. This usually can't blush. And you won't need to wash it between laminations.
The brand you are using will tell you their limits on the MSDS or data-sheet.
If you are unfamiliar with epoxy in general, it might be better to go with someone's system. Usually it is supported with literature and tips. Working with epoxy is straight forward and no big deal - except for the money and maybe the time ballet.
Any fillers I would make with the same epoxy and cabosil and microballoons.
There's plenty here on the board on that.
Depending on the brand of epoxy you can work down to 45 degrees but the stuff gets thicker and harder to mix. I use laminating epoxy ( and slow hardener, usually) because it is not viscous. Generally, I think epoxies like 55 to 65 degrees - inside you should be able to produce that. If you are using no solvents, a cheap cube catalytic type would be perfect.
C'pete on another thread is correct in saying that all of your repair can be accomplished from the inside, leaving the outside for fairing.
The bigger the hole the more feathering overlap onto undamaged hull you need to grind and then build up with layers of mat and/or fabric. You can add, on the inside, extra layers of reinforcement. That's what I would do. There should be a smooth transition between the new work and the old.
Your damage looks like three or four feet long??? You can glass in a stringer like backup that 'dies' into a good part of the hull or stops at a glassed in bulkhead. Maybe it can be part of the furniture.
Or, like Geoff and others have done, you can glass in extra vertical 'knees' or locker dividers behind the settee.
Working inside you can heat the space, and direct heat on the work.
If you use 'pealply' or even plastic wrap you can get your repair smooth enough so that, if you have to stop and come back for more laminating, you can continue with minimum grinding ("sanding"???).
Definitely, the worst thing about frp is making glass particle dust. My hero vac doesn't suck it up so if I lean with bare arms inside I'm prickled for the next 3 days!
Is there anything wrong with doing this in two steps? Our concern is keeping the shape of the hull. We've got stands on either side of this damaged area as well as 4 other supports evenly placed around the hull. The bulkhead is out and can't be replaced until we fix the damaged area on the inside. Some of the delaimination is behind the bulkhead.
If the hull loses its shape, we are in truly bad shape. I don't know if we can fix it then. Right now, the glass is so thin that light comes through it - bright light. We want to lay up the interior and then work from the outside. It seems like the only way to do it.
And yeah, ebb, that's about 4 feet of delaminated glass that we've removed and the place where the jack stand had been is delaminated all the way through. It looks like the hull was punctured not once, but 3 times. It must have been a rock, but what an impact!
Cap Crunch,
The boat ought to be balanced (and it would be easier later if square and level also) so that the jacks and props are not, and cannot possibly, distort the hull. Possibly improvise level (waterline) of vessel by checking (with carpenter's level) the bunk in he V-berth and settees in cabin.
They are designed to the waterline and should also be 'level' athwartship. You hope.
After 40 years the hull is not going to change shape.
Find and lay out one foot intervals on BOTH sides of the hull where your damage is. Make vertical templates of the good side and use them at the 'stations' to check your progress or deconstruction. Do a lot of measuring to get the placement. Take measures along the hull, take measure from the stem fitting back on deck on both sides. I would probably use the toe rail to key and hang the templates on. If the boat is square and level on its waterline, you can get an acurate perpendicular with the templates.
The four or five templates are just guides that will help to keep you within the parameters. One assumes the original mold the boat was laid up in was exactly the same both sides. Sure.
When you get to the exterior (step two?) after your repair you will be using a longboard sander on the fairing compound which will fair your repair into the rest of the boat. I would also use a 6' aluminum batten (described elsewhere) to check for hollows and hills. The upshot is that the final stroke of perfection might not exactly fit the templates of the opposite side. Should be close, but it don't matter.
Don't know your two step. Have fun with it.
I thought we covered this:
IMCO one way to insure the integrity of the hull SHAPE at the damage site is to laminate on a layer of xmat without regard to the damage. If your approach is to do all your repairs from inside, I would slap on a layer on the outside, just prepare by removing paint down to gelcoat, paste it on up on to the good stuff - you'll grind that off fair later. If breaks have caved in you could push them back out with props and battens gluing them in place. Whatever you build up, whatever mistake, whatever hollows, can always be grinded away! That stablizes and gives you a bottom to grind down to from the inside if that is what you do. You may not need 'templates' this way. {Believe I would remove ALL the damage, clean it up down to good glass - then figure out a way to repair the hole.
Spring battens over the hole migjht work well. Correct thickness so they won't flatten, keep their curve.
Might actually glue them on to the ouside of the hull - try double sided carpet tape first - make sure it stays there. Possible the battens could be zapped right to the hull with sheetrock screws, right thru the hull!!! Wrap the battens in SeranWrap where they span the gash.
Then span the damage from inside with X-matt. Then laminate more and fill and fair to a semblance of the original. These are merely ideas, there is always another way to do the job!
I think the boat got bounced up and down on the rocks for a while to cause that damage. You might find some filled chunks down at the bottom of the keel.
I've used the cold weather hardener from raka.com. Says its good down to 40 degrees. On a warm day it will cook off pretty quickly.
I would also grind the ends of the shelves back a little so you can tie them into the new bulkhead.
Try to line up the new bulkhead and new glass so that you can use the existing chainplate slot through the deck without having to move the slot over.
I just don't think its necessary to root out every bit of old delaminated glass. Your new epoxy and glass is going to have phenomenal strength.
The glasswork actually goes pretty quickly, like making lasagna. Just slap it on there.
If you wanted some reinforcement you could install another shelf. I added one on each side to get more usable storage.
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