Chop Saw blades?

Phoneguy

MGF, Master Grumble Framer
Joined
Dec 1, 2004
Posts
678
Loc
New Westminster, B.C. Canada
A couple of comments on my fillet chopper search have started me thinking about tools that I already own, not specifically for framing.

I have a 10" Delta chop saw that has mostly been used for finish carpentry. I have it built into my workbench so (assuming it isn't cluttered) I have about 10 - 12' to the right of the cutting blade and 5 - 6' to the left. I do have proper jigs to verify my chop angles when needed (Lee Valley makes wonderful stuff)....So the question is:

I have heard from some framers that a reasonable quality 80 tooth blade (eg from Frued) does an acceptable job. Other framers have said don't bother unless you get a blade specifically made for chopping picture frames.. What is peoples feelings on this?

In my own case, I would likely only use this for chopping down/recycling older mouldings. For the time being chop and join is very economically viable for me....still there is the odd time....

Thanks All
James
 
Hi James,
My family has a saw business - been in the business since 1845. A few weeks ago I had the same question so, I asked my father what he suggested : an 80 TPI or 100 TPI for cutting mouldings. He set me up with a good 80 TPI blade - and it is working well - the cut is very smooth (I do have a guillotine trimmer and use it to 'correct'). The moulding companies that use the business saw sharpending services also are using 80. I figured if it was good enough for them it should work for me.
Hope that helps!
Jody
 
I use a Forrest 80 TPI Chop Mater blade on my 10" saw which costs around $110. My mitres are flawless. They just came out with a Mitre Master that runs around $200 for the 10" 100 TPI blade which is specifically designed for cutting mitres, hence the name. Both are hand straightened to eliminate virtually any run out.

Regards,
Barry
 
James, you can spend up to $300 for a ceramic 10" blade and that might be worth it if you cut a lot of frames per day (I don't know since I've never used one). We cut and join at least 30 frames a day mostly on a Pistorius MN100 and we've spent at least 25 years testing blades. If you're cutting picture frame molding with gesso or plaster (any leafed molding) you won't get a better blade than a Freud LU 85 (we currently have 24 of 'em) The problem with cutting gessoed molding is that the plaster(or whatever it is) dulls any carbide blade faster than you'd think and it doesn't matter if you pay $200 for the blade or $50 in the case of the Freud. Freud,btw, is the largest maker of woodworking tooling in the world and they're good at it. If you're hellbent on spending more than $50 for a blade, consider the Freud F80 for around $100.

You'll be way better off buying two Frued blades and sharpening them often than buying a $200 industrial blade designed for 12 hour continuous days. The $200 blades may do a bit better cross cutting very hard woods, white oak and hard maple, but I'm not convinced.

Getting good miters from your cutoff saw will depend way more on clamping than the blade. The reason for using top quality (and either Freud blade is one)sharp blades is to prevent tearout as the blade exits a cut in a leafed, gessoed molding.

The Freud F80 will cut veneered plywood good side down without tearout and that's as hard a test that I know of. The Lu 85 is about as good and won't dull as fast since it has fewer teeth and clears out faster and runs cooler. I don't think anyone does a better job cutting frames than we do and we like the LU 85's a lot. We also run a complete cabinet shop and we use Freud blades there, too. I really like the thin kerf rip blade; on our 5 hp Unisaw, it sings through wood.

We have Forrest miter master and ultimate cut off blades to compare the Freuds to. The Forrest blades are good blades but expensive, especially considering how often any blade cutting leafed molding has to be sharpened. We change blades about avery 300 frames, about once a week.
 
For what it's worth, I finally took Warren's often touted advice and bought 2 10" LU 85 blades to compare them to my Forrest blades which I have been using since the early 90's.

To make a rough comparison of the LU 85's vs. the Forrest blades in smoothness of cut, I would compare them to 80 Grit sandpaper vs. 400 Grit sandpaper. Both chopped good angles but the LU 85's had so much white wood showing on the edges of the miters that I finally took them back and got a refund. I almost sent them to Forrest to have them resharpened to see the difference but I figured that, in the long run, I was kicking a winning horse in the garbonzos by spending that much time and energy when I had a couple of good sets of blades to begin with.

Just one man's opinion but I can vouch over a span of 16 years for the consistency of Forrest blades both in accuracy of cut and also in smoothness and long life between sharpenings. The grade of carbide, I think, is a grade or 2 better than Freud, C-3 or C-4 carbide instead of C-2 grade.

But if you don't mind sharpening blades every couple of weeks, almost any half way decent blade should do ya.

Framerguy
 
I don't want to seem overly argumentative but I have to point out that we have hundreds of hours testing crosscut blades and we can find no difference in quality or service life between Forrest and Freud blades. We've tested Freud LU85s against Forrest Miter Masters and Freud F80 blades against Forrest Duraline HI-AT blades. Recently _Fine Woodworking_ tested Dado sets and the Forrest Dado King didn't perform as well as the Freud set.

At to carbide, Freud uses super micro grain carbide which is only inferior to ceramics,
and it's a good bet that Forrest buys their micro grain carbide from Freud since Freud is the major supplier of carbide powder to the tooling industry.

Just to be sure, this morning I made 4 cuts into Omega 78666 (a 1/2 inch leafed molding that we think is one of the most difficult to cut without tearout at the back where the blade exits the cut)with LU 85's on our MN 100 and the cuts were perfect, no tearout at all (these blades are going on their second week or over 300 frames). BTW, the quality of the cut on the face of the mitre is irrelevant; tearout is the issue. My guess is that smothness of cut on the face is a function of runout at the saw's arbor amplified by any in the saw blade. Blade runout can be ameliorated somewhat by rotating the blades on the arbor. Freud uses high speed steel with a Rockwell rating of between 40 and 45 for it's blade blanks. The blanks are tensioned on a cnc machine for very little runout. We look at the back of the cut right at the bottom and only super sharp blades will cut this stuff with no tearout. Carbide is carbide and plaster is plaster and plaster will dull carbide quickly, requiring frequent sharpening at industrial shops (we use Quality Saw and Knife)for top quality cuts and we demand excellent cuts. I noted on the saw, these blades will be changed on Monday.

We only use Miter Masters on our metal saw (Pisterious EMN 200) because metal doesn't dull blades as quickly as plaster, not nearly as quickly, and we haven't tested Freud 12" blades as extensively as we have the 10" blades. We use Freud "Plexiglass" (LU94) blades, both 10" and 12" for cutting acrylic on our SCMI SI150 and our Unisaw and they do an outstanding job. Interestingly, when we have to mitre really wide molding (over 5 1/2" wide) we use a Freud blade on a sliding table saw (it can cut 18" mitres)and get an excellent cut, face as smooth as glass almost and no tearout.

I just got through looking over our corporate tax return and noted we spent a little over $2200.00 in '04 for sharpening blades. Believe me, we have a lot of experience with tooling.

Anyone coming to Wilmington for that POS symposium May is more than welcome to bring along some difficult molding and make a few cuts on our saws and see for themselves how LU 85s peform. In fact, if any Grumblers are comming to Wilmington, plan on having a BBQ (southeastern NC style, the only real BBQ) and drinks (irresponsible behavior) at my house. Make reservations early and I can offer a room.
 
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