Freud LM74 Glue line – Not Overwhelmed

[Bruce Page]

Quote from Freud:
“This blade's specially designed triple chip tooth design produces extremely smooth true surfaces for gluing & finish work. There is no need for sanding or jointing after the cut. The ideal working range is from 1/8" to 1" thick.”

I picked up the LM74 last weekend to rip some thin strips of 1” QSWO. The hope was that I wouldn’t have to do a lot of sanding. While the LM74 breezed through the 1” oak with very little effort, the cut surface was less than I had hoped for. The strips required a fair amount of sanding to remove the blade marks.
I used my standard ripping setup of feather boards & a smooth, steady feed rate.

I should have just used my Woodworker II, it leaves a much better finish.

I’ll keep the blade because of the low cutting effort but I won’t count on it for glue-up or sand free edges.

[Brian Hale]

Hey Bruce!

How high was the blade set? I keep mine so it's only about 1/8" above the thickness of the material and get a better cut surface than my WWII. If i raise the blade higher, the cut quality drops significantly.

Brian :)

[Mark Rios]

I also get Glue-up ready cut surfaces with that blade. I like it very much. I own two.

[Bruce Page]

Hey Bruce!

How high was the blade set? I keep mine so it's only about 1/8" above the thickness of the material and get a better cut surface than my WWII. If i raise the blade higher, the cut quality drops significantly.

Brian :)
Brain, maybe that's it! I had the blade set so the gullets just cleared the board - my normal mode. I'll try lowering the blade as you suggest and see if that helps.
Thanks.

[Ed Hilton]

I asume the blade is parallel to the fence, and it's not warped.

[Allen Bookout]

What did you find out Bruce?

I just ripped some 3/4" red oak with a new Infinity 24 tooth rip blade and there are no blade marks. Very smooth. I did set it with the teeth just slightly above the wood. I would think that the Freud blade should cut as smooth.

Allen

[Robert E Lee]

Bruce, there is something wrong some place, you should be getting a nice smooth cut. I would check all your settings then call Freud maybe you have a damaged blade.
Bob

[Howard Acheson]

This is what Charles M. from Freud says about blade height for their bladesl

"When using the correct Freud blade for the application you will only need the blade 1/8" to 1/4" above the material."

[glenn bradley]

Glad to see your post. Keep experimenting awhile. I had very disappointing results from my WWII when compared to my Freuds and posted my experiences just as you have on the glue-line. After some feedback from Creekers who use the WWII, we are now starting to become friends.

[Dan Gill]

Bruce, it's just possible that you got a bad blade that made it through the QC with problems, or that has been damaged. I had to return a Freud blade to the blue borg a few weeks ago. It was a model I've had before (and ruined somehow), but the initial cuts with it were very, very ragged. Back it went. I actually ended up buying another Freud blade from Amazon, one they didn't have at the borg.

[Jeffrey Makiel]

To echoe what was said above about blade height, I believe the Freud Rep (who frequents the wood forums) said that 1/2 the height of the carbide tooth. That is, the tooth should not be fully exposed above the work.

As a side note, I have a lot of Freud blades and think highly of them. However, I don't own the LU74 (yet). But the variety of other blades I have, including the previous LU72 rip blade, have performed very well.

-Jeff :)

[Bruce Page]

I didn’t get a chance to work with the LU74 over the holiday weekend but I suspect that I had the blade too high. All of my past experiences with Freud have always been good. I’m using a dialed in Unisaw so I’m sure that it is not the problem. Hopefully I’ll get a chance to use it tonight.
Thanks for all of your help.

[Scott Whiting]

A glueable surface for a joint does not have to be perfectly smooth. It needs to be straight and have no marks deeper than .003" which can be seen with the naked eye but won't weaken the joint.

[Dave Lehnert]

A glueable surface for a joint does not have to be perfectly smooth. It needs to be straight and have no marks deeper than .003" which can be seen with the naked eye but won't weaken the joint.

I was told by a Freud rep that the glue line rip blade was not made to produce a glass smooth surface, but a slightly rough edge, so the glue had something to grip on to.

[Bruce Page]

I was told by a Freud rep that the glue line rip blade was not made to produce a glass smooth surface, but a slightly rough edge, so the glue had something to grip on to.
Dave, you may be right, but that goes counter to Freud's advertising line that I quoted in my original post. “This blade's specially designed triple chip tooth design produces extremely smooth true surfaces for gluing & finish work. There is no need for sanding or jointing after the cut. The ideal working range is from 1/8" to 1" thick.”
Brian probably hit the nail on the head when he suggested that I had the blade raised too high above the board. I've been working some long hours so I still haven’t had a chance to put the blade back on the TS and give it another shot.

[scott spencer]

Dave, you may be right, but that goes counter to Freud's advertising line that I quoted in my original post. “This blade's specially designed triple chip tooth design produces extremely smooth true surfaces for gluing & finish work. There is no need for sanding or jointing after the cut. The ideal working range is from 1/8" to 1" thick.”
Brian probably hit the nail on the head when he suggested that I had the blade raised too high above the board. I've been working some long hours so I still haven’t had a chance to put the blade back on the TS and give it another shot.

AFAIK, the LM74 has a fairly shallow side clearance to help give the cut edge a more polished/burnished character.

[Charles McCracken]

AFAIK, the LM74 has a fairly shallow side clearance to help give the cut edge a more polished/burnished character.

Scott Spencer is correct that the side clearance angle on the tips of the LM74 series blades is very low to produce a smooth edge. All of the advice so far has been excellent and I agree that the blade height is the place to start and 1/2 carbide tip above the material is usually ideal. Bruce, please keep us informed as to the progress.