How or what do I need to make a 16' knotty alder handrail blank to put in a moulder to create a 16' knotty alder handrail for some customers? Can I offset the joints when gluing? I don't have a finger jointing machine either.
(Architectural Woodworking Forum)
From contributor H:
Yes, you can do it that way - we do it all the time - 12' & 4' & 4' & 12'. Just cut the joint ends at 45* and make sure they are tight.
We use a Garniga adjustable finger joint head on a sliding table shaper. We just set up the new Gartop arch press for doing arch segments of curved windows and doors. It also works well for pressing straight runs of moulding together. Not a high production finger joint system, but good for the custom shop. Finger joints are not historically correct joinery, but using alder, its probably not a National Historic Record job. Contributor H's method or some kind of scarf joint would be more correct for that. The trim carpenters seem pretty happy to get the finger jointed material for their long runs.
In the shop tips from Cabinetmaker magazine they mentioned a shop cutting kerfs on finger jointed arch segments to pull them together with spring clamps. Probably a good solution if you only do it occasionally. Not an application for straight runs though.
We are doing some 20 long alder beam wraps next week and will try to post pictures of our system.
The first picture shows the positioning device with the boards ready to be clamped. This bar has a spreading adjustment to control the glue line. At first we had a small gap on one side of the board. With a little adjustment both sides are closing tight. We just did a 3 thick window head test today and it was slightly open one side. I think this was due to poor clamp position and will work on that tomorrow.
We have found we need to leave the 20 pieces setting for a couple minutes before moving. The shorter and thicker pieces can be handled right away.
This picture shows the boards pressed. By pushing both buttons the clamps engage and the right table moves. With clamp time controlled by a timer.
Cutting 78mm thick window head with Garniga adjustable finger joint cutter. Profil 45 sliding table shaper.
3 piece 78mm thick, 30 degree arch pressed.
That the press does straight runs easily is a plus. With the amount of curve work we do the return on investment would be slow. To be able to add value to custom millwork by joining long lengths accurately and strong is a bonus for both the shop and trim carpenters.
Moulded and sanded alder finger joint.