Tool for cutting "fingers" into the ends of a stud?

[cjard]

If you take your hands and spread your fingers apart slightly you can then interleave them. I'm wondering if there is a tool that is maybe like a series of X mm saw blades, mounted X mm apart that one can use to cut fingers into the end of the stud, the idea being that two studs could then be dipped in glue and the fingers knocked together.

Kinda like multiple small mortise&tenon joints, but with the aim of making one long piece of wood rather than a corner

The query comes about from looking at the engineered I joists I have.. the flange seems to be formed into a continuous run from multiple short lengths, every now and then the flange exhibits a triangular wiggly line where an interlocking triangle pattern was cut into the ends of two bits of wood, then they were glued together. Of course, the same happens with the osb web and the other flange but never in the same location as any other joint. I have hundreds of offcuts of timber, all a bit short for the purpose I need, but if I could joint them reliably..

 

[Burnerman]

Try googling 'finger jointers' and you should find something you can use with a router....seen them but never used one!
John

 

[Deleted member 174758]

If your timbers are of any decent size (i.e. over 1-1/2in thick) then you start to get into the territory of spindle moulders, power feeds and finger jointing sets - at megabuck prices). You'll also find that the strength of the finished items is pretty variable - if you've been looking at proper glulam then surely you are aware that those boys aren't jointing 3in long pieces (because the main strength is derived from the long edge to edge glue joints). The other thing is how will you manage to hold a 10ft length of glue jointed 3in pieces together under the required amount of pressure? If you can't manage that you may have problems getting a reliable joint. Far easier and more reliable to simply buy decent fresh timber in the correct lengths to start with. My own approach to dealing with short offcuts is called a wood burner.

 

[cjard]

Aye.. This is in an application where I've got loads of circa 800mm long 3x2 offcuts, and I could do with some continuous 3x2 rails held against rafters (counterbattened) every 600mm, about 4 metres long. The thinking was if there was something like a jig and pack of saw blades that I could plunge each end of the offcut into and then joint I could have fixed it in place and left it. It's going beheind plasterboard so I'm not really bothered about ugliness, straightness etc

I'll hang onto them for another application and get some new lengths, relative cost of messing with the offcuts versus buying new lengths it's gonna be cheaper to buy some more in..