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epoxy not holding

Posted: Mon Jan 16, 2012 2:59 pm
by toolman
I glued up my first strip but it did not hold .Is there something I'm doing wrong or should I coat it first with epoxy.Also is the precoat resin and hardener or just resin?

Re: epoxy not holding

Posted: Mon Jan 16, 2012 4:00 pm
by cjbfisher
Toolman,
I'm definately no expert, but I'll try. Your first "precoat" should be unthickened resin and hardener, then the next should be slightly thickened. Then clamp your two pieces together with just enough pressure to hold them together. Too much pressure will force the epoxy out of the joint and weaken it.
The first "precoat" will soak into the timber, and will stop the epoxy being sucked out of the following coat. If you didn't "precoat" the timber, the epoxy in your slightly thickened coat would be sucked into the timber, and the joint would be weakened.
Hope this helps.
Chris

Re: epoxy not holding

Posted: Mon Jan 16, 2012 5:35 pm
by jem
Can you expand on what you mean by first strip? Some more detail on what you're doing will help.

Re: epoxy not holding

Posted: Mon Jan 16, 2012 5:44 pm
by toolman
I put my fisrt strip on the forms I used hot on glue at the forms ,I had a joint about the middle and that is where I used the epoxy as well as at the bow stem and stern stem.I'm working on the freedom 15 strip.

Re: epoxy not holding

Posted: Mon Jan 16, 2012 6:02 pm
by jem
hmmm...

couple things may have happened:

-You might have got the epxoy mix wrong. (did you add fiiler like woodflour?)
-You squeezed out all the epoxy like mentioned above.
-The wood might have had some oil film or something on it.

Re: epoxy not holding

Posted: Mon Jan 16, 2012 8:09 pm
by toolman
I did not notice anything on the wood and no I did not use any filler Should I use filler in it even when I get to the point of gluing the strips? also I got my first strips from the paddle company today,it was Ash and red cedar ,they are all cut to size planed and angle cut on the edges so I'm ready to start installing them once I get the problem with the first strip straightened out.

Re: epoxy not holding

Posted: Mon Jan 16, 2012 8:33 pm
by tx river rat
If I understand correctly you are strip building this boat ?
Why are you not using titebond II or III to splice your strips
On your first strip ,a full length strip or a splice on your forms will save a lot of problems and the you have something to clamp onto for the next strips.
Ron

Re: epoxy not holding

Posted: Mon Jan 16, 2012 10:07 pm
by jem
If using as glue, epoxy needs a little thickener to hold in place or it'll run out of the seam/joint. I learned this the hard way on the first boat I built.

Titebond II or III is typically used for wood strip boat building as Ron said. It's different than epoxy in that it likes good clamping pressure. Won't be as strong as epoxy (but still more than strong enough). Strip building with epoxy will end up heavier and MUCH more expensive.

Re: epoxy not holding

Posted: Mon Jan 16, 2012 10:21 pm
by toolman
where can I get tite bond?

Re: epoxy not holding

Posted: Tue Jan 17, 2012 7:18 am
by jem
home improvement stores, hardware stores, wally world, it's pretty common.