Finger-Jointed Wood from 2x Scrap
A discussion about the practicality of turning off-cuts into useable studs by finger-jointing. July 30, 2007
Question
My father has a large source of 2 by 4 and 2 by 6 cut-offs, at least a semi load a day. He is considering a business of turning the cut-offs into finger jointed lumber. I assume companies make dedicated equipment for this, as you can buy finger jointed 2 by 4s. The idea here would be to use a cutoff saw to square the ends, and then ideally there is a machine that allows you to just feed in random length boards and the machine would finger joint both ends. I assume you can buy a machine that would glue and RF cure the joints. I'm picturing an assembly line kind of thing. Labor is fairly cheap where he is, and with the right equipment, skill level needed would be low.
I have tons of experience in cabinetmaking, but no experience with heavy equipment like this. Short of waiting for the show in Atlanta in August, where do we start looking? Is this an incredibly stupid idea? I think the source of the cut-offs is giving away today to someone who grinds and sells the chips for livestock bedding. Are we looking at $50K, or $500K?
Forum Responses
(Solid Wood Machining Forum)
From contributor D:
The first thing I would consider is what you would use the jointed boards for. You can not market them as stud grade lumber. I had a job that generated a large amount of 2 by 4 shorts and was at a loss as what to do with them. I looked at doing what you are proposing. By the time I paid for the tooling and set up, there was not much profit in it. Wound up giving them away.
From contributor S:
You should also realize that finger jointed lumber is typically oversized when finger jointed, then S4S planed in one quick pass. This is what straightens and trues the inconsistencies in the rough stock.
It sounds as if you do not have this option, so you would have to be extremely accurate in your joining (impractical), or S4S to an undersized dimension after joining. Then what do you do with it?
Back up and look at turning this scrap into clean white shavings for the show horse people. They buy baled shavings for bedding their animals, and they pay quite a bit for it.
From contributor L:
Way back in the day, I worked in a place that used this idea for door and window frames - clear wood for stain and f/j for priming and painting. Also, they made some and tooled into different types of moldings. Actually anything that is of a decorative nature could be made from this product for a painted finish. Check out the big box stores for ideas and wood shows. Since it's a value added product, you should have a niche. Only drawback is the machines. One finger joiner with glue and air operated, depending on the lengths you make, could eat up a lot of shop space and you would be looking at storage and material handling equipment. Great idea, though.
From the original questioner:
Can you elaborate on why these could not be marketed as stud grade? In California, finger jointed studs sell for a premium, as they stay straight. I assumed one would have to go through a process to have the product and process certified.
From Professor Gene Wengert, forum technical advisor:
The manufacture of finger-jointed 2x4, 2x6 and so on is done throughout the entire world. It is only recently that it has been done in North America.
I am not sure what contributor D means when he says it cannot be graded.
Although there are many machines, you might start with looking at Auburn Machinery. Note that many operations use a stress rating machine to bend the lumber to find weak points and also find the overall strength (estimated). This lumber is called MSR lumber (Machine Stress Rated).
I would encourage you to look for small business loans and other assistance in forming the business. Effort now will avoid problems in the future.
From contributor D:
The Wood Doctor is correct about fg studs, however the problem I had was this. First, a 2x4 scrap has radius edges. When the scrap is fg together, the fingers protrude out the side of the radius. Second, after the scrap is assembled, it is not exactly straight. To solve the two problems I just mentioned, the stock needs to go into a moulder to be straightened and the edges eased over. The end result is a 2x4 that is not 1.5 by 3.5. This is also assuming that the shorts you are getting are of stud grade quality d-fir, h-fir.
From Professor Gene Wengert, forum technical advisor:
Are the cut-offs already KD and planed? If so, contributor D is correct. If they are green or unplaned, then no problem.
From the original questioner:
The cut-offs are from a very large rafter operation. They are already KD and planed. I'm not sure how consistent their current dimensions are; I'll have my father get some and check consistency. I wonder if I could just run them through a moulder to radius the edges a little more to smooth them out enough? I guess it all depends on how consistent the scrap is.
I was assuming that the machinery would very precisely cut the joints so that they were consistent and square. I was also assuming that the automated gluing equipment would hold the stock straight when ultrasonically gluing.
