THIS IS A VERY IMPORTANT POST.
Don't just glue up the layers and leave them to dry for a few hours. You have to check the laminations every few minutes, reposition and slide the laminate sides back into position.
Gluing up the laminations is tricky! Read this entire post before layering up your fins.
You've got to use enough glue to guarantee complete side to side coverage. On the left is how much glue I used. On the right is the glue smoothed out with a fingertip.
But -
The glue makes the layers slippery!
When the glued pieces are pressed together, they will slide.
Line up the first two layers as best you can, use your block to get the root edges flat or slightly recessed as shown in the last post.
Some would be tempted to use Super Glues from the outside of the joint seam - don't!
Super Glues won't give you a strong complete seal. When the fins are sanded and shaped, you might find the layers opening up.
You'll need a heavy, flat weight to set on the glued up pieces, like a few very heavy books. I used a marble slab from my leather working days.
After placing the weight on the aligned glued fins, the pieces can slide from their original position.
YOU HAVE TO GO BACK AND CHECK THE ALIGNMENT EVERY FEW MINUTES before the glue sets up. I set the audible timer on the Microwave for three minute intervals.
The outside layers can open up, warped from the wet glue.
I set a bit more glue inside and spread it out with my knife. Back under the weight to dry.
As you are checking the fin layer alignment, remove any glue that has squeezed out at the root edge.
It's easier to remove the glue before it dries. That glue bead won't allow a close fit against the body tube.
Long time lurker, rare commenter... I'd just like to say I'm glad you're back blogging some builds, especially challenging ones like the BB XII. So far, this is great!
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ReplyDeleteThanks for the warning on slippage. To mitigate it somewhat I used a variation on the double-glue method. Using my finger, I smeared a thin layer of glue onto both the core and one outside part, covering them completely, except for the tang. Having a rag handy is paramount. The glue is mostly absorbed into the wood. If the glue is thin enough, it will start to tack up quickly. Then I spread another thin layer on both pieces, lined them up, and immediately and placed them under a stack of books. I did check them twice ( 4 and 8 minutes). Slippage was none or minimal. I used ply cores. This probably reduced warping.