To Gel or Not to Gel - That Is the Question

[s/v Jedi]

Originally Posted by Fishman_Tx

As for the rest...
Holy Sh*t, sounds like you done this before!

Not on Jedi yet, fortunately ;-) Friends with a cat just removed the flip-it-and escape-hatches and closed those (big!) holes so it's fresh in my memory ;-)

cheers,
Nick.

[Fishman_Tx]

Uh oh, problems in those areas? I'm considering a cat for my next boat....

[James S]

Nick is right...Removing the gel coat top sides means hundreds of hours of fairing...this kind of fairing requires a damn good hand and eye if you don’t want it to end up looking like Ferro cement.

[s/v Jedi]

Originally Posted by Fishman_Tx

Uh oh, problems in those areas? I'm considering a cat for my next boat....

If deck hatches leak what do you think happens when you install them an inch or two above the waterline ;-)

cheers,
Nick.

[Fishman_Tx]

True THAT
Guess they decided the weren't needed anymore..

[Fishman_Tx]

Originally Posted by James S

Nick is right...Removing the gel coat top sides means hundreds of hours of fairing...this kind of fairing requires a damn good hand and eye if you don’t want it to end up looking like Ferro cement.

Yep, It could get nasty. I just don't want to do all this work and expense just to have it come back to haunt me later. As for the cracks, few are "treatable" in-situ as most are fine stress shears; large patches of fine chevron shaped cracks. Refer to the pic with the red arrow and look above the arrow and waterline. There is a pencil mark going fore to aft. The stress crack are is about 3ft long and extends 18 inches above that line. And thats just one patch.

Is there a way to stabilize it? Several epoxy overcoats...or something...

It took a bit for me to get the hang of using the grinder with 50grit, granted my initial efforts were dicey. The product after doing one side below the line (other than the blisters) is really smooth seeming and the chop is still there (This boat has a VERY thin layer of chop under the gel). The gel being softer than the chop came off easily (when wet) with the 50 grit. Our initial attempts with 36g were WAY too aggressive.

BTW, never did find out what the Black layer was under the gel....

[s/v Jedi]

Originally Posted by Fishman_Tx

Is there a way to stabilize it? Several epoxy overcoats...or something...

The description I gave will completely stabilize the cracks but I think you mean the rest of the surface to prevent new ones? Yes, you can do that but make sure the prep is done well. Machine sand with an orbital sander and 80 grit. Do a quick wet sand by hand with 80-120 grit and rinse with water. Again, try not to contaminate the surface by touching, cloths with solvent etc. Roll a couple of thin coats of epoxy on, the second on the gelled but tacky first coat. These coats take much longer to cure than filled blisters so use regular/fast hardener, which also minimizes amine blush. The painters will take over after that and should start with wet sanding it (must be done wet).

If the paint job is not done right after the coatings, you must protect it against UV damage. The easiest way (I would do this anyway) is by adding some white pigment to the epoxy that's rolled on. Use the one from West System to prevent compatibility issues (it's formulated for epoxy) and don't add more than allowed (instructions are on the product bottle). The white color will also be appreciated by the painters.

I really don't think the cracks sound very bad. When pieces of gelcoat are missing and falling off when tapping it, that's bad. You seem far from that.

cheers,
Nick.

[Solitude]

Fish
Is there a logical reason for the stress cracks?
Chainplates or bulkheads... I am not the expert Nick is but wouldn't it be an idea to try to stablize the cause. Add glass to the bulkhead/hull joint or stiffening it with glass over a form if there are cracks along a weaker area? On the inside.

[Solitude]

[FloridaWriter]

Originally Posted by Fishman_Tx

Yep, It could get nasty. I just don't want to do all this work and expense just to have it come back to haunt me later. As for the cracks, few are "treatable" in-situ as most are fine stress shears; large patches of fine chevron shaped cracks. Refer to the pic with the red arrow and look above the arrow and waterline. There is a pencil mark going fore to aft. The stress crack are is about 3ft long and extends 18 inches above that line. And thats just one patch.

Is there a way to stabilize it? Several epoxy overcoats...or something...

It took a bit for me to get the hang of using the grinder with 50grit, granted my initial efforts were dicey. The product after doing one side below the line (other than the blisters) is really smooth seeming and the chop is still there (This boat has a VERY thin layer of chop under the gel). The gel being softer than the chop came off easily (when wet) with the 50 grit. Our initial attempts with 36g were WAY too aggressive.

BTW, never did find out what the Black layer was under the gel....

Fish,

Regarding the cracks in the gelcoat in the topsides, some of them sound like they may be related to the damage that was repaired by the "patch". If those cracks are structural they need to be ground out, perhaps glassed and filled (with epoxy--no polyester resin, please!). The cosmetic cracks are from age, UV damage and perhaps the gelcoat applied too thickly 40 years ago. They should be sanded enough that you can apply thickened epoxy over and faired.

DO NOT remove the gelcoat to the topsides. Instead use it as a reference to fair against, sand the areas that need sanding with 40# or so, wet out the areas with unthickened epoxy to seal. Then fair with epoxy thicked with a high density filler like West 404. Use a board sander to keep from dishing the fairling and use the remaining gelcoat of the topsides as a guide and reference to what you are fairing.

As to your barrier coat, I would do a minimum of 7 coats of West epoxy--the more the better. It is not necessary and buys you nothing to apply additional coats when the previous coat is still "green". Simply wash each coat with water and a 3M scouring pad and dry thoroughly. Remember to protect the barrier coat from sunlight and UV until you get bottom paint on. Neither the barrier coat additive from West, nor the pigments have any UV filters in them. I would not spray the barrier coats. It is very easy to apply them with a roller and tip with a foam brush, and get a very smooth finish. The Geugeon brothers in their boat repair manual give the minimum thickness required for barrier coating, but I don't have it with me here.

The fiberglass under the gelcoat is a charcoal gray color on my B29; I don't know what would be "black" under it. Keep in mind that the yard was famous for hiring Portugese fishermen during their off season to help with new construction, which accounts for some of the strange anomalies we see in old gen-1 Bristols.

Good luck!

[Fishman_Tx]

Originally Posted by s/v Jedi

I really don't think the cracks sound very bad. When pieces of gelcoat are missing and falling off when tapping it, that's bad. You seem far from that.

cheers,
Nick.

Only a couple of those on the starboard side gun'l that'll need to be built up and shaped and a few "chips" here and there (same side as the patch) mainly on corners and edges.

Heres a pic of "Before". The red box midships shows the gouges from the dock. The box forward is one area of stress cracks. As you can see from the topside condition of the bow, a lot of gel is going to go away. Lots of recoring to be done. But, Hey! We got her cheap, so I can't complain. You buys your ticket and you plays your game!

BTW, Nick, I'm printing out all these pearls of wisdom!

[Fishman_Tx]

Originally Posted by Solitude

Fish
Is there a logical reason for the stress cracks?
Chainplates or bulkheads... I am not the expert Nick is but wouldn't it be an idea to try to stablize the cause. Add glass to the bulkhead/hull joint or stiffening it with glass over a form if there are cracks along a weaker area? On the inside.

From smacking a piling and the dock I think (the patch is just below), plus it's old. I think the gel may be "rotting" as she hasn't had any love at all for a long time.

[Fishman_Tx]

Originally Posted by FloridaWriter

Fish,

Regarding the cracks in the gelcoat in the topsides, some of them sound like they may be related to the damage that was repaired by the "patch". If those cracks are structural they need to be ground out, perhaps glassed and filled (with epoxy--no polyester resin, please!). The cosmetic cracks are from age, UV damage and perhaps the gelcoat applied too thickly 40 years ago. They should be sanded enough that you can apply thickened epoxy over and faired.

DO NOT remove the gelcoat to the topsides. Instead use it as a reference to fair against, sand the areas that need sanding with 40# or so, wet out the areas with unthickened epoxy to seal. Then fair with epoxy thicked with a high density filler like West 404. Use a board sander to keep from dishing the fairling and use the remaining gelcoat of the topsides as a guide and reference to what you are fairing.

As to your barrier coat, I would do a minimum of 7 coats of West epoxy--the more the better. It is not necessary and buys you nothing to apply additional coats when the previous coat is still "green". Simply wash each coat with water and a 3M scouring pad and dry thoroughly. Remember to protect the barrier coat from sunlight and UV until you get bottom paint on. Neither the barrier coat additive from West, nor the pigments have any UV filters in them. I would not spray the barrier coats. It is very easy to apply them with a roller and tip with a foam brush, and get a very smooth finish. The Geugeon brothers in their boat repair manual give the minimum thickness required for barrier coating, but I don't have it with me here.

The fiberglass under the gelcoat is a charcoal gray color on my B29; I don't know what would be "black" under it. Keep in mind that the yard was famous for hiring Portugese fishermen during their off season to help with new construction, which accounts for some of the strange anomalies we see in old gen-1 Bristols.

Good luck!

The white gel is very thin in places (2 seconds to remove) and when ground away the black layer is between the gel and the chop but is way thicker than the gel but just as soft.

No "Hot" topping, got it

Ok I think it was 6-9 mils minimum, I read somewhere.

[Fishman_Tx]

Originally Posted by Solitude
The links I sent have some good info from the Gougeon Brothers West system.
They are one of the leaders in the area.

Sry forgot to respond..... Yup, I have read and printed the entire collection. Even the stuff that don't apply; and put it in a binder for quick access.

[Christian Van H]

Originally Posted by FloridaWriter

It is not necessary and buys you nothing to apply additional coats when the previous coat is still "green". Simply wash each coat with water and a 3M scouring pad and dry thoroughly.

I simply do not know where some of this information comes from. There is a difference between "Hot Coating" (which really just means the previous coat is VERY slightly tacky) and a scrub with scotchbrite... A CHEMICAL vs. MECHANICAL bond. Also, FWIW, I prefer MAS epoxies. They have two different viscosities and are more flexible over all when cured. A coat of low viscosity followed by 4 coats of their FLAG higher viscosity both hardened with their NO BLUSH medium hardener (for 65 deg. and under) will do it. If you have any questions at all about your project, you can call MAS and speak with the OWNER! MAS: Epoxy - MAS Epoxies: Home - Build & Repair Boats & Marine, Non-Skid Repair, Cars & Automotive, Woodworking, many other projects - Composites, Fiberglass Resins, Hardeners, Glues, Adhesives I buy from: Boat Building and Woodworking Supplies If you join their VIP club, you get free ground shipping on EVERYTHING for a year...

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