To Gel or Not to Gel - That Is the Question

[Fishman_Tx]

At what mix ratio?
Actually, believe it or not, the gel came off with 50grit on a 7" sanding disc fitted on a 3300 rpm grinder leaving 99.9 percent of the chop intact. Very smooth once one got the hang of it.

BTW, the blisters are getting "rebuilt" not just filled. just to clarify....

[Maine Sail]

Originally Posted by Fishman_Tx

At what mix ratio?
Actually, believe it or not, the gel came off with 50grit on a 7" sanding disc fitted on a 3300 rpm grinder leaving 99.9 percent of the chop intact. Very smooth once one got the hang of it.

BTW, the blisters are getting "rebuilt" not just filled. just to clarify....

We used 75/25 75% Aerosil/25% Milled Fiber.

If you are fairing below a barrier coat using micro-balloons is ok but I still prefer coloidal silica.


This bottom was faired/filled with Aerosil/Milled Fiber including the keel and keel joint. We found two areas where the PO had used micro-balloons and a couple areas where "Bondo" had been used. Both areas read high moisture and were removed. The area's of Bondo filler were actually flaking off...

[Fishman_Tx]

We're down to raw glass but will apply 1-2 coats of epoxy without barrier additives before rough fairing and 5-7 with 422 afterwards. Following the West System schedule...for the most part.

[s/v Jedi]

Fish: just keep looking at that photo from Maine Sail... that's where you want to go. I agree with the 75/25 mix too. The colloidal silica is anti-sag so makes the fairing easy. Don't mistake this with a high density filler, which is much harder.

cheers,
Nick.

[Fishman_Tx]

No mistake in that. Thats what we're using for the deck hardware...

[Fishman_Tx]

Ok, here's the patch. A few pics below. Cat hair mixed in the epoxy. I ground the center to see the depth and what was below. No cloth, only gel, as I figured it would be. So, it's gotta come off.

[Stillraining]

Ah...feline fiberglass.......well what ever you have on hand at the moment I guess..

[Fishman_Tx]

I guess so, they sure didn't bother to remove the gel for a proper patch. Dang thing is 3/4-1" thick. Oh well, grind...grind.. and grind some more.

[Fishman_Tx]

So, what do you think folks; build up the depression w/cloth/roving/epoxy or grind it all out to "hole" and start over? Remember it is behind (splits) one of the bulkheads...

[s/v Jedi]

Looking for shortcuts?

;-)
Nick.

[Fishman_Tx]

Nope just what would be best, proper thing to do. The area is still depressed 3/4-1" and has cracks that were patched over in the interior. It is not "holed" under the patch. This is going to get ground out to the raw glass on the exterior. Inside behind the bulkhead is a patch area that is roving and epoxy and displaces the bulkhead a 1/2" off the hull when in the water. I guess what I am asking is:

1. do we attempt to remove the depression by flexing the hull outward(relieve) after grinding all the patchwork out, inside and outside?
2. do we fabric-fill, and fair the exterior, leaving the depression and interior patch alone?
3. do we grind the entire thing out to a big-assed hole and start over?

I'm afraid we may have to "hole" it and start over. As bulkhead displacement occurs only in the water but not on the stands. But I may be just paranoid too. May be it's because we have other issues like soft decks?

Thx!

[s/v Jedi]

no.3

get that thing out and see what happens. grind all the patches on the inside away, all that was done to patch this up must go.

You do no want a depression.

cheers,
Nick.

[Stillraining]

Grind it out and start over...not a big deal.

[Fishman_Tx]

Oh it's flex cracked, but not holed. Interior roving/epoxy cracked(split) under the interior cloth.
Nick:
Ok then, It's a good thing I printed all this out... place the exterior "sandwich" and screw to the hull... right. <whimpers>

[Solitude]

You're going to be an expert by the time this is over! You could fund this repair by writing a book.

Just copy all the text and send it to an editor and presto your very own DIY guide.

Good work! Ive been playin in the snow so... I missed a bunch but I read you were concerned about the dificulty in sanding colloidal silica. I really didn't find it too bad on mine and it is the prefered solution so a little extra elbow grease would be worth it. I used my DA sander.