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Adhesive in a scarf

Posted: Mon Sep 25, 2006 8:18 am
by TreelineIII
I am scarfing together some pieces for the garboard as well as some of the side strakes. I will also be laminating up a few pieces of white oak to make the keelson, then setting it in bonding to screw in the hull. What adhesive would you use in these applications? I am going towards using 3m 5200 on everything. All of these joints are perminant and likely in some way be in contact with water. It seems that the 5200 will seal voids and make a better sound joint then regular epoxy. Thanks for your help
Eric

Posted: Tue Sep 26, 2006 4:17 am
by a j r
I don't know about 3M5200 for a scarf joint. Do some research at www.woodenboat.com in their discussion forum and maybe post your questions there.

Andreas

Posted: Tue Sep 26, 2006 7:53 am
by txcaptdan
I have only used epoxy for scarf joints, you want these to bond into one piece not with a gasket between like 5200 will do. Epoxy absorbs into wood better that 5200 and becomes a part of it all.
Good luck

Posted: Tue Sep 26, 2006 7:11 pm
by JoeCB
Use epoxie for perminant joints that that you are making in the reconstruction of original wood pieces. For example scarf joints in repaired ribs, strakes or garboards. Think of 5200 as a gasket material to be used to seal the "temporary" joints between two pieces of wood.
PS how's the wood working out for you ?
Joe

Posted: Wed Sep 27, 2006 6:14 am
by TreelineIII
Joe, you are the man. This last week I cut the White Oak down to size and then finished the sides. It is better then I could have ever asked for. Thanks. I am getting the okoume ply this weekend. So if I understand from the glueing comments here is what I plan to do. In the scarf joints of the ply I will use epoxy. When bedding the keelson using 5200. and for the bolted laps I was thinking 5200.
However I continue to think that I am making this more difficult then necesary and think I should just use different thicknesses of epoxy for everything. ?????

Posted: Thu Sep 28, 2006 4:56 am
by john
Nice thing about 5200 is you don't have to mix it. Plus it does not run like epoxy.

When using 5200 on laps, use mahogany if you can, it is less noticeable when it get out of the joint.

There is use talk of white oak and epoxy not being the best, although thats's what I used. Two part resorsinal is considered the best for white oak.

Posted: Thu Sep 28, 2006 3:13 pm
by JoeCB
I also have heard that epoxie on white oak is less than optimum, however that is what I have used with good success. Also, consider thickining the epoxie w/ one of the commercially availaple powered fillers. This gives a less runny consistency and helps fill less than perfect joints...
Joe