14 replies to this topic

[Boudicca]

I've done some balsa core replacement from inside the cabin on my '81 J/24. It was surprisingly easy after some setup and planning.

Now that's done, I'd like to replicate the smooth lumps that it came with before I paint it. I'm thinking this looks like thickened resin applied with a long napped roller.

But, thinking has gotten me in trouble in the past. Has anyone figured this out? I have a strong sense that I may make a royal mess and waste materials only to discover this isn't how they did it.

[lake Pee]

Make some test pieces to see if it works like you think it will, before you mess up all your hard work.

[Kaptainkriz]

make a latex texture mold from somewhere else on the ceiling.....

[Overbored]

most likely it is sprayed or rolled on gelcoat. unthinned gelcoat sprayed on will give a orange peel or a finish that looks like small bumps. rolled on gives a finer texture to the finish. if useing gelcoat on an surface it will need to be one step or cover with pva or hairspray to keep the air off for a complete cure.

[Ishmael]

Remember they put it on upside down...it doesn't work the same way defying gravity.

[Billy O]

I just did the top on the j35 this winter.

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[Billy O]

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After repairing the affected area I sanded the whole ceiling, stopping at the transition at the side walls. then I skim coated with low density filler, and resanded the ceiling smooth.

Then I rolled on one coat of primer and one coat of one part polyurethane paint (with 7 inch WEST system foam roller) which I painted the the whole cabin with.. Let that set a couple of days. (Mix some colldial silica with your paint as as a flattener)

Next, go buy some sponges and tear out small sections of them wit needle nose pliers. This will be your texture applicator. Thicken the heck out of some your paint with colldial silica and apply to ceiling, dabbing slowly with a sponge. It took me two passes to get it right. (Don't go back to correct paint that starts to tack up, fix it on the next pass) You can blend the texture down into the sidewalls so any slight difference in texture pattern won't be as apparent.

Let that set.

Keep enough paint with some flattener mixed in to re roll for a color blend if needed or touch up.

It's a trial and error process. Patience is huge.

[berioska]

I just did the top on the j35 this winter.

 c1.jpg   196.68K   39 downloads

 c2.jpg   193.18K   30 downloads

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 c4.jpg   206.1K   25 downloads

how could you handle lamination overhead? How did you approach it?

[Billy O]

I did it in sections. I wrapped luan in plastic and used that with 1x2 jacks or "kickers" to hold the new core in place. After that dried, for gap filling along the sides between the old and the new, I used WEST SIX10 which has zero slump and is ideal for working overhead. Then I did my multiple layers of glass laminate, rolling with 105/206 and a 7"WEST roller, lightly sanding between coats. I then rolled a barrier coat of straight 105/206 and skimmed with low density to fair.

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[Billy O]

Before I reglassed I had to come up with a plan for epoxy bushings for the bolts around the winches. You can see a few old ones stubbed down in this pic before I got rid of them.

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So I took a small bit and drilled down from the deck in the center of the old bolt holes, then marked my depth and drilled back up with a 1 inch paddle bit, stopping just short of the deck. The remaining balsa I cleaned out with a small chisel. I then put a 1/4 inch deep "shoulder around my new holes with a router to help reduce stress around the expoxy/balsa border.

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Then I filled the holes with WEST SIX10. Despite the terrific anti slump properties of that epoxy, I filled them in three passes to prevent any possibility of voids.

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EDIT: I also added the "1/4 inch deep shoulder with SIX 10 around the entire perimeter of the repair, as well as at any new to old balsa joints.

[berioska]

thank you Billy for your explanation. just one question: did you applied even the glass layer with the "kickers" to hold them in place?
I'm going to do the same core replacemend on my boat all around the mast step.

[foredeck1916]

I've done some balsa core replacement from inside the cabin on my '81 J/24. It was surprisingly easy after some setup and planning.

Now that's done, I'd like to replicate the smooth lumps that it came with before I paint it. I'm thinking this looks like thickened resin applied with a long napped roller.

But, thinking has gotten me in trouble in the past. Has anyone figured this out? I have a strong sense that I may make a royal mess and waste materials only to discover this isn't how they did it.

Why bother?


Textured ceilings are against the OD rules anyway -


R2 D2 1.2: The application of materials to create textured ceilings in the cabin are prohibited.



why would you want to add weight to the deck anyway?

[USA190520]

Really? Fuck, I just installed a tin ceiling with 8" crown mouldings.

I guess the mirrored part in the bee birth is also out...

[foredeck1916]

R2 D2 69: Stamped ceilings are permitted only if you have a porcelain head.

[Billy O]

thank you Billy for your explanation. just one question: did you applied even the glass layer with the "kickers" to hold them in place?
I'm going to do the same core replacemend on my boat all around the mast step.

No, I didn't need to. I rolled on the epoxy with a WEST foam roller and let that set for 20 t0 30 minutes, then i laid the glass on, smoothing by hand. Then I wet out the layer with more epoxy and a foam roller using moderate pressure. When wet, the glass should be pretty transparent and any areas that appear opaque typically will point to air behind the laminate. You can get them to adhere with your finger (use gloves). Sand LIGHTLY between coats. If you have small valleys they will be apparent after you sand. Wipe the area down with a damp rag of alcohol, let dry and then skim coat with 407 (or 406) to ensure a flat substrate for the next layer. (If you skim coat you'll need to lightly sand those areas again and wipe down with alcolhol before applying the next layer of glass.) I put four layers of glass on the cabin top and a 3" band of fiberglass
reinforcing that spans the perimeter from new to old. I laid seven layers of glass under the starboard primary winch and reinforced that perimeter as well while I was at it. The winch leaned forward under a heavy load for years and I expected it to be wet balsa. When I opened it up I found it wasn't wet at all but the balsa had fractured and compressed over time so I reapired that area while I was at it. After glassing I probably applied 3 coats of fairing over the top of everything, sanding between coats and finally rolled on a THIN layer of unthickend epoxy, sanding lightly again before appying primer.

I used the slow hardener and allowed at least 24 hours between each step (sometimes more) as I did it over the winter. Fortunately we keep the boat in heated storage so the epoxy kicked off just fine.

I don't know how much glass to tell you to use around the mast step on your J24. You may want to be sure it's beefed up and if you have access to a pro who could advise you, you may want to consider doing that before proceeding. Fortunately I live in te same town as the Gougeon Brothers and I am friends with some of their technical advisors who coached me through this, and other projects I've tackled over the years. Good luck.