Straight Line Rip Saws for Glue-Up

A good straight line rip saw makes rips you can glue up with no further processing. Here's advice on choosing and maintaining your machine. July 28, 2008

Question
I have a small hardwood custom furniture making shop and am getting into producing large runs of cabinet doors for other local shops. I used to plane and edge joint all boards to be laid up and glued for panel stock. There is simply not enough time in the day to continue doing this. Will a straight line rip saw produce an edge ready for glue up as does the jointer, or would there still be another process of jointing or using a moulder to produce the clean edge that I need for glue ups? Any advice would be helpful.

Forum Responses
(Solid Wood Machining Forum)
From contributor A:
All major furniture manufacturers make their joints on a SLR or a gang rip. The question of which is better - jointer or rip - was settled over 50 years ago. When I first started with my Dad, there were still a very few plants that ran jointers. No more. Now, don't tell me that you make better furniture than the mass producers, because I believe it. However, there are some decent sized plants that make very good solid furniture. My pick of the bunch is Henkel-Harris, Winchester, VA. They make solid cherry dining table tops and triple dresser tops, grain matched so well that to the ordinary consumer it looks like it is make from one piece of wood.

When you rip parts out of a board and then go to a jointer, you lose 1/4" from each board because the jointer is most likely set for a 1/8" cut. It does not sound like much, but at the end of the day it gets expensive. Second, tests have proven over and over and over that a sawn joint glues better than a knife cut joint, especially when the knives start to dull. You do have to learn how to maintain and adjust the machine, but when you do, you have a much better operation.



From the original questioner:
Thanks for the information. There must be a myriad of machines with differing specs on the market. I don't mind investing in myself with a quality rip saw, but I have never used one before. Will they allow the operator to adjust the width of rip after the initial straight edge rip in order to compensate for varying widths of boards? Would you recommend a particular machine with low production in mind but where extreme high quality is a must?


From contributor B:
If you want to glue off the saw, insure two things:

1. That your saw is capable of this and set up to do so,
2. That you have the proper blade(s) and sharpening service to do this.

Not all SLR's are equal, new or used. Some simply can not be rated for glue line accuracy. Others will do only 4' long pieces, or 8' or whatever. Some will do all lengths, all day, every day. We would glue up 16' skirtboards off the saw and never had a problem with the saw. The lumber was rough or skip planed, edged on the ripsaw, glued into wide panels and then ripped to 12" and S4S'd thru a big 4 head machine.



From contributor A:
As you say, insist on a warranty, a demo or both. Obviously I would suggest either Diehl or Mattison in a used saw over the many copies or attempted copies. Diehl would be first choice because they are still very much involved and give great service. The Mattison machines are very good also, but the service and hand holding is not there any longer.

Be aware that a new chain, track and drive sprockets for either will cost more than the price of a good used saw with good chains on it, so be very sure that the used machine has been used for joints and that the chain and track are in near perfect condition. I do not have anything to offer at this time, so I am not grinding my own axe. I don't know how this saw will be used, so I can't reply to the width question. High production plants have several rips in a row, each ripping one width at a time from one length. The ideal set-up would be a laser to edge and then the fence for the width. For instance in these lines a certain rip saw is assigned 38" lengths to be ripped to 2" widths, two trucks at the outfeed end. Edge the piece, rip all of the 2" it will make and the leftover odd width goes on the glue-up truck with the 2" on the main truck.



From the original questioner:
I contacted Diehl today and although they are very pricey, quality must be achieved. They have some very nice equipment and very helpful sales people. I think this is the route to go. I appreciate your comments.


From Gene Wengert, technical advisor, Sawing and Drying Forum:
Remember that it is the sides of the teeth that actually prepare the surface to be glued. Therefore, proper sharpening will include side-dressing. It is surprising how often glue joints from a SLR saw can be improved by getting better sharpening...you may have to try several shops to find one in your area that is good.