Marine glue for wood boat

What plans are you using?

 

Polysylfide is the usual choice in a traditional lap.

 

I bought them online several years ago,called "Banksdory.com"

 

So,what adhesive would you use in place of Bostik 920 which the plan calls for....??? How about 3M 5200?

 

Bostik Marine 920 from http://www.bostik-us.com/market-products/transportation/marine:

Bostik 920 suppliers:
http://fiberglasssupplydepot.com/BOSTIK-MARINE-920.html
http://www.mscdirect.com/product/details/03353893

3m 5200 from http://solutions.3m.com/wps/portal/3M/en_US/Adhesives/Tapes/Products/?N=5510818 3294314620&rt=rud

 

Polyurethanes used under the LWL, need to be in a pressurized joint, for the full length of the cure (often over a week). This usually isn't a problem with lap joints, as they tend to naturally pressurize the joint, during assembly. I've seen polyurethane (3M5200 specifically, but typical of polyurethanes) used over carvel seams and it pulls right out in one long rubbery string, if used topically. This is why polysulfides are preferred (3M101).

 

Thanks folks, I will post pics if I can....

 

The boat is under construction....Pics will follow as I progress...am using Bosik 920....seems to do the job.

 

Bosik 920 is a polyurethane, so make sure it's clamped up good and stays that way for a few days. Is the laps are mechanically fastened, these will provide enough clamping pressure if fairly closely spaced. It's not as tenacious as 3M-5200, but still is a good sealant/adhesive, particularly with fasteners backing it up.

 

How do you post a pic?

 

Click on "Go Advanced" on the quick reply or click the blue Post Reply button, then click Manage Attachments and you can upload images with your post.

 

Fore and Aft

Fore and Aft

 

Loved PAR's tips page for background! Written so even *I can understand it.
Will next try to understand where flex in a design meets material stiffness or lack thereof.

 

Thanks Art. Think of stiffness (or lack thereof) as a shoe. Yep a shoe, ever wear a clog or other supper stiff, non-flexible style of shoe? Some folks swear by them, but you wouldn't want to go dancing in them. The same applies to boats. Stiff is nice, unless you're getting your butt whipped in a hard slosh to windward, with 25 - 30 knot winds pounding you. This is when flex is a good thing, both for you and the boat. She'll be able to absorb and more importantly, dissipate impacts and other loads, so your butt isn't hammered as much and the structure can absorb more strain. Rigid things tend to break all of a sudden, once it's fully loaded, while flexible stuff tends to yield and return, just to yield again.

 

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