[bhcva]

I am repairing the damage done by a leaking staysail fitting and am down to refilling the rotted core area. It's an irregular area that has been hollowed out surrounding the 3"x1/2" slot...from less than an inch to 2-3" laterally. The only way I can think of, to ensure the hole is completely filled, is to pour a very liquid, but thickened, epoxy into the slot and let it flow where it will (the bottom is sealed). I'd then have to re-rout the slot. The first question is: is a thickened epoxy that is liquid enough to flow to all corners going to be thickened to the degree that it should be in cases like this? The deck slopes slightly on both sides away from the slot so the flow should be ok. I will do anything to preclude having to drill holes thru the deck to inject the thickened epoxy. Injecting or packing a more thickened epoxy sideways would seem to make it difficult to be sure that the cavity is completely filled.

A second question: does this hollowed out area need to be pre-coated with unthickened epoxy?

Thanks for any and all advise.

Bruce

 

[scottyt]

okay i am not an expert, but what i would do is

first straight epoxy has problems with multible things. first it likes to kick too fast, and its not very strong on its own. thickened epoxy does not like to run out very well, and thinning it so it flows will cause problems in an enclosed space.

i would open the slot about another half inch on the sides, so it measures 1 by 3. then drill a few small holes around the edges where you have it decored, and i mean 1/16 inch holes. basicly drill one every 3/4 to inch around the perimeter.

then get some 6 or 7 oz glass cloth, and rip it apart so it just a bunch of fibers. using what ever tool you can pack this around the edges of the perimeter to a depth of about 1/2 inch. then pack in some unshredded cloth in the hole to fill it. dont pack it so solid it cant move but say a 80 to 90 % fill.

then using card board make a tube that it about 6 inches tall that you can tape over the slot. then mix some normal west system ( or what ever brand ) epoxy, with about 5 % acetone and slow or extra slow hardener, then fill the tube. the weight of the epoxy in the tall tube will help force it down into the glass. you will need to top it off a few times as it works in. if you dont get some very minor seepage out of the small holes, then take a small shop vac and put it over the holes and turn on the vac for a second, until you get some epoxy out of the holes. you could even use a piece of tubing and suck with your mouth. then let it cure for a few days.

after it stops settling you could remove the tube before it cures. i would leave the tube until it cures completely then just cut off the cardboard and epoxy tube.

another option is to pour in the epoxy and use the shop vac on blow and put air pressure on it until it comes out the holes. but i still think the time method of a tall tube would be a more complete fill.

 

[sailingfool]

Yikes..you want to thicken the epoxy with collodial silica, make it the consistancy of runny peanut butter. Buy a pack of plastic syringes, use them to fill the hole by starting at the deep corners and working your way around. Straight epoxy is brittle, not to be used other than as a coating. As to whether to pretreat with straigth epoxy, I don't think you'd need to, but you might look at some of the West systems literature. You can get all the needed stuff including syringes from West Systems.

 

[joethecobbler]

Pour in the epoxy and let it run into all the places it will. Then after it sets go back and place fiberglass roving into the void and pour in another epoxy batch. repeat this until it's full to your requirements. Don't waste alot of time and money on a complicated fix for a simple problem.
Also, the epoxy is much more solid and much less brittle than polyestor resin, so don't be too concerned about not getting alot of fiberglas roving coverage.
Remember, with the rotted wood core removed it will be much stronger than when it was cored !
Then launch and sail.

 

[mitiempo]

Hi
If the gap is only 1/2" x 3" you probable aren't able to put a lot of roving in there. I would used straight epoxy with slow hardener and fill the slot totally. Wait a few minutes and then remove the epoxy which is easy with a syringe. Then mix colloidal silica with the removed epoxy until it's thick but still self levelling in consistency. Inject to fill completely and let cure.
Brian

 

[mitiempo]

Here's a great reference - West Epoxy's Fibreglass repair manual. Ain't the web great - I had to buy my copy but that was 15 or so years ago and now it's free.
Brian

http://www.westsystem.com/ss/assets/HowTo-Publications/Fiberglass-Boat-Repair-and-Maintenance.pdf

 

[bhcva]

Thanks all for the advice

As noted in the OP I don't wan't to put any holes in the deck that I can never bring back to original condition so I believe I will go with Mitiempo's suggestion after experimenting a bit with using the syringes.