Wht oak lamination in progress

[gapup]

Continuing with the saga of damaged frame tops, the longest piece to be scarfed is
roughly 48 inches overall length. Sided 3 inches and molded 1 3/4. The turn at the
chine forms a radius of about 12 inches and straightens for the last 10 inches or so.

All in all, the piece forms roughly a 45 deg angle from head to toe.

The above attempt to describe the thing will hopefully give the next guy some idea of
where to begin for lamination thickness.

With only limited experience in laminating, the first two attempts ....... dry runs ........
resulted in kindling and experience. The laminations were too thick, 3/8 and 1/2 and
both were flat sawn.

Today I found some quarter sawn oak and very nice stuff it is. Laminations were sawn to
5/16 and planed to just under 1/4. The stack of 7 laminates measures 1 11/16. With
allowance for the splooge (epoxy mud), the end result will still likely end up over 1 3/4
on the fat dimension.

Long and short of it is, the entire stack is now under clamps as a dry run and no
fractures have taken place. On to the next step. Sand off the machine glaze,
apply splooge and reclamp.

[Mrleft8]

I'd suggest (just a suggestion now....mind you....)that you soak your laminations in hot water for a half hour, reclamp them wet into your form, and let them sit over night. Remove them from the form and separate them and let them dry out. THEN spooge them and reclamp them to your form.

[gapup]

Mrleft8 :

I had considered something like that but was concerned about the residual moisture level and its effect on the epoxy bond. And winter is coming and I need to get these repairs done so I can continue replacing the deck.

In any event, I just now finished putting it all together and there was no problem at all. Maybe the dry run loosened things up.

If there is a lesson here, it's that trying to cold bend flat sawn stock will not be a gratifying experience. Better to find a length of VG stock and proceed without hassles.

[T.KAMILA]

Gapup,
When I laminated the frames for my catboat I steamed them for the first clamping instead of soaking. It was white oak sawn to thickness without planing or sanding. The steam doesn’t really wet the wood it mostly heats the wood. In fact it is said that the steam keeps it from drying out too much. The steam also raises the grain a little allowing for good toothing of the glue joint. I glued with (rescorcenal?) glue keeping things warm while curing.

Worked for me,

Tom

[Bruce Hooke]

FWIW - In replacing the laminated stem on a small rowboat I used the steam and then glue method and it worked fine with Resorcinol. However, when I needed to add another layer to the stem and tried to use epoxy, the glue joint failed so badly that I could easily pop the new piece off with a screwdriver. I've always guessed that the steaming somehow contaminated the surface in a way that was very incompatible with epoxy. To solve the problem I heavily sanded both surfaces to get rid of any contamination and then reglued -- and appeared to get a good joint. Since then I've concluded that it usually seems to make sense to either steam or laminate but not mix the two unless absolutely necessary.

[Peter Malcolm Jardine]

I second the resorcinol with white oak experience... found it works more reliably for some reason.