Lapstrake hull seal/refinish

[trebot]

I have a 23' Chris Craft Sea Skiff. The hull had been fiberglassed. I removed all the glass cloth and re-fastened the entire hull. I was planning to seal each lap with 3M 5200 and then re-glass the hull. If there is a better way (and hopefully easier), I'd appreciate your input. After reading other posts on the subject, I'm wondering if thickened West System epoxy instead of 5200 would be better at the lap joints. Will it flex with the hull or crack? Will epoxy without the cloth work on the entire hull or should I re-glass the entire hull? Also, what is "gluvit". Thanks!

 

[Jeff Goldberg]

Re: Lapstrake hull seal/refinish

Is this a Lapstrake boat or plank? If you re fastened you may not have to use glass or 5200 try swelling the boat and see how she holds water.You either need to float it for a couple of weeks and watch it, or fill it on land and let it soak for a couple of weeks.If its still not as dry as you would like it then glass or 5200.You would have to make sure there was no 5200 exposed because the resin wont bond to it if you were going to try both.I used 5200 and it worked well.Although I prepped well.You really should fabricate a tool that will let you get about an eighth of an inch into the seam so you can get the old caulk out and a good bead of 5200 in.The only down fall of the 5200 is that if you ever decide to take the boat apart for further restoration it will pull the wood out with it.I swear by the west system I'ts very strong but if this is a Lapstrake boat that kind of boat is meant to flex and I could see problems down the road unless you could make sure the hull would'nt flex as it was designed to.Gulvit is a seam sealer but I tried it and it didnt work well as i did'nt have good access to the seams from the inside.I would go with the 5200.Good luck.

 

[petrolhead]

Re: Lapstrake hull seal/refinish

Chris-Craft Sea Skiffs were built using Thiokol adhesive sealant for the laps, that's a flexible "rubber" type product. I'd use the nearest modern equivalent to reseal yours. <br />Personally I wouldn't glass the hull again, just rub down and give it a couple of coats of epoxy resin then paint it (I assume the hull will be painted, not a natural wood finish?).

 

[BillP]

Re: Lapstrake hull seal/refinish

Thiokol equivalent would be polysulfide. Like my other posts on this topic say, I wouldn't glass either. Epoxy resin would be my first choice and 5200 second if too lazy to remove all paint. Third and easiest would be polysulfide...But polysulfied won't glue the laps and the others will.

 

[trebot]

Re: Lapstrake hull seal/refinish

Based on everything I've heard, I plan to: Dig out and clean lap joints; fill with 5200 (3M says epoxy will bond to 5200); sand hull and coat with Gluvit (the mfg says it flexes much better than regular epoxy); paint hull with marine quality paint. I really don't like the idea of glass cloth (to rigid), so I'm not going to use it. Here we go! Thanks for your input.

 

[petrolhead]

Re: Lapstrake hull seal/refinish

The sealant really only needs to seal the laps, they are (or should be) rivetted with copper nails as well which give the joint its strength.