Lapstrake sealant

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62cruiserinc
Posts: 21
Joined: Mon Apr 19, 2010 7:44 pm

Lapstrake sealant

Post by 62cruiserinc »

When I reassemble the lapstrakes on my 62 Cruiser, Inc., what sealant should I use?

I know the strongest sealant/adhesive would be the 3M 5200. In doing a search on this site, it looks like some controversy over using the 5200 for the lapstrakes, mostly based on the difficulty of removing the lapstrakes in the future. However, if the renovation is done right, there should be no need to disassemble for many years.

I would like to hear suggestions for the sealer.

West Marine has tubes of 5200 on sale this weekend for $9.99, so I may buy the stuff there if I decide to use it.

Steve
Phill Blank
Posts: 412
Joined: Thu Jan 05, 2006 4:20 pm
Location: Hurley, Wisconsin

Post by Phill Blank »

Steve,

5200 can be used, as you said if the restoration is done correctly one should not have to be doing it again in their life time. Boatlife is also a good one to use. It also is not easy to remove once installed and cured. Main thing is that both of these are flexible when cured that give then the long life and they both have good adhesion on properly prepared materials.

Go for it & Good Luck,

Phill
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john
Posts: 261
Joined: Tue Dec 27, 2005 7:33 pm
Location: Crosby (Houston) Texas
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Post by john »

How much sealant was still holding, when you removed your lapstrakes, mine was maybe 20%, but probably closer to 10%.

I used 5200, zero problems with leaks, after 6 years

Biggest problem I had with 5200 was excess sealant, sqeezing from between lapstrakes. Started out with white 5200, changed to brown, very quickly, does not show as much as white.
62cruiserinc
Posts: 21
Joined: Mon Apr 19, 2010 7:44 pm

Post by 62cruiserinc »

I think about 20% of the sealant was still holding.

How did you clean off the old sealant on the lap area? Sanding?

Also, how much work time does the 5200 give you? I need enough time to put in almost 100 screws for that row.

Finally, how many tubes of 5200 will I need to buy? I have 8 laps on each side of a 16' boat.

Good suggestion on the brown 5200 to keep it from showing inside.


Thanks for the suggestions, Phill and John.

Steve
john
Posts: 261
Joined: Tue Dec 27, 2005 7:33 pm
Location: Crosby (Houston) Texas
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Post by john »

I cleaned off old sealant with a paint scraper, came off easily. Made sure all sealant was gone to clean wood with small hand plane or 4" 10,000 RPM grinder with 30 grit paper. Same grinder I used to shape the new inner keel, best tool I've found for boat building.

Work time with 5200 is several hours, even at 95 degrees. Was more of a problem dripping than it ever was setting up to fast.

Did not use a lot, maybe four tubes at most, does not take a lot. Thin bread goes a long way. Tried to have just a extremly small visable amount showing after tighening screws.

Think I started to reasemble with garwood first, last lapstrake was fun!

20% still holding, that means 80% of seams would leak if not redone! Sealant needs to be between the lapstrakes not on outside. Outside caulk at lapstrakes is for cosmetics and just a backup seal.
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