Excuse me if I’m a little rambly…
I’m resawing some Bubinga. My test case was resawing a 2 inch thick piece of Bubinga about 5 inches tall by 38 inch long into 3/32 inch thick slices, and my 1 1/2 hp delta bandsaw with a 3/4 inch 3 tpi hook tooth blade did ok. Stalled out once or twice when I was pushing too hard, but it went through it without too many complaints. Ended up making 10 cuts.
I’m now starting into the real project, which calls for resawing 8 1/2 inch tall Bubinga into 3/32 inch thick slices. It’s very slow going. The first pass went ok. On the second pass I noticed it was burning the dust a bit … it was mostly red tinted with flecks of black in it. And the saw kerf had some brownish tints from getting too hot. On the third pass, it’s slightly worse, even though I’m not leaning into the work so much. Ultimately I need to make a total of about 50 cuts like this for this project (and next project might be worse).
This project is a serpentine front chest of drawers, and these will be vacuum lamination parts for the drawer fronts. This is a learning step for eventually making a china hutch that will also be of Bubinga and will likely call for resawing a bunch of wood.
I presume I’ve overheated the teeth on this blade and lost their temper, or dulled them with the exercise, and now the blade is toast. I expected to learn from the experience.
The question is, with a bunch more work to do, is it worth buying a replacement of the same caliber ($25 blade purchased at Woodcraft, as I recall, I don’t have the box here at work) and just being more careful not to lean into the cut so hard? Or is it really worth the extra dollars to get a carbide blade? In theory, a carbide blade shouldn’t be as worried about a little heat, but the price makes me hesitant to conclude that heat is the only thing I’m learning about here.
Do the Woodslicer or Timberwolf blades really perform way better and longer in use like this? The sales pitch sounds good, but it’s still asking the blade to do a lot of work, and that much work is going to create some heat, and they’re still capable of loosing their temper and that’ll be that?
Replies
Scott --
In my experience in resawing, a blade works fine until it starts to go bad, and then it goes bad in a big hurry. My theory is like yours: that when the teeth start to get dull, the tips heat up and loose their temper, so they get duller quickly, so they heat up more, and so on.
Over the years I've tried lots of brands of blades, and gotten similar life from them, except for Timberwolf. The Timberwolf blades I tried went dull very quickly, despite their good reputation on the various woodworking forums.
I've found that for resawing that tall, a 2 TPI blade lasts lots longer than a 3 TPI. It has a bigger gullet, so the sawdust doesn't get packed in to insulate the tooth tip.
Scott,
I did a quick search on the machining properties of bubinga and both references mentioned moderate to severe dulling of cutting edges. This may be an application where buying a carbide tipped blade is worth the investment, given how much cutting you have to do.
John W.
try for a stellite 3 tpi. or carbide. 'binga is really tuff on blades, and hard to boot.
another option ( my first thought) use fewer laminations of the bubinga and laminate a face veneer to a sub core..of say, solid sawn poplar.
Go Stab yourself Ya Putz! Ya think I Parked here?
I think Scott should save his money on carbide and go for a 2/3tpi variable pitch bimetallic blade. The variable pitch makes sense on hard timbers because it will reduce the tendency of some blades to start oscillating (harmonics) which in turn messes up the cut. I feel thet the Delta simply cannot tension the thcker body of a carbide blade properly (the Lenox TC blades we use on a 28in Agazanni require 25,000 psi - 2-1/2times or more the max. you will ever get out of a Delta 15in saw) and the smaller wheel diameter will possibly lead to premature cracking or failure of the welded blade joint. I also doubt that you'd see a stellite blade this small - they are made by spotting a glob of stellite onto a pre-ground and welded blade body then profile grinding to shape - normally something you'll only see on large resaws (the type with 36in or larger wheels). If you still want to look at carbides then the two makers I know of are Lenox (American Saw) and Simmonds.
Perhaps if you talk to Louis Iturra of Iturra Design in Florida he might be able to give you better advice on this - Louis sells carbide blades (Lenox Trimaster) and knows the Delta saw very well. BTW, his catalogue is worth getting for anyone who bandsaws.
Scrit
Edited 1/31/2004 6:43:21 AM ET by Scrit
Edited 1/31/2004 6:46:42 AM ET by Scrit
Your saw blde is being run at too fast of a speed. You should change the drive pullies or perhaps install a variable speed drive.
Re: the WoodSlicer, I found that it performs outrageously well at first, but dulls outrageously quickly. I mentioned this anomoly to the guy at the MiniMax booth at the Denver woodworking show, and told me that it is a modified meat-slicing blade, not made from a steel designed to cut wood. I've had better luck with TimberWolf, but never used a resaw blade.
Charlie
I think it would be worth calling Suffolk Machinery and asking for one of the techs, tell him what you're up against here and get his recommendation. Then ask why that blade would do better than the competition. Suffolk (Timberwolf) has 4 different lines of blades, and getting the right one for the right task is important (dare I say "obviously"). I just ordered 3 blades -- one PC, one AS, and one HK, each for a different wood/task combination.
I would be very curious what they'd recommend -- either the PC or the AS. The PC cuts very smooth but runs slower than a typical hook-tooth blade. Here's what they have to say:
The AS, on the other hand, is specifically designed for very thick wood (6-8"):
[edit -- then again, there's the AS-S which is specifically designed for straight-line veneer cutting. Sheesh, maybe that's the one]
My Grizzly bandsaw, which has a 1HP motor I think, absolutely rocks with the right TW blade in it. Next week, I'll install the riser kit and resaw some 6" cherry and some 10" maple -- will let you know how it goes, LOL.
Oh, here's the link where I got all that stuff:
http://www.suffolkmachinery.com/importantinfo.html
forestgirl Another proud member of the "I Rocked With ToolDoc Club" .... :>) you can take the girl out of the forest, but you can't take the forest out of the girl ;-)
Edited 1/31/2004 7:18:38 PM ET by forestgirl
Here I go a-rambling again.
Well, went shopping 'til my wife was dropping in town today (Portland, OR). Hit Woodcraft, and looked over what they had in Timberwolf, but nothing in my length for in a 3/4 inch blade.
Saw Rockler briefly, but all I saw there were carbon blades too.
Hit Woodcrafters (not related)and looked at Lenox blades. They really surprised me by having something in the store in something other than carbon steel. They had both a bimetal blade, and a carbide blade. Lenox had the blades labled that the carbon blades were good for soft woods, the bimetal good for hardwoods, and the carbide was recommended for tropical woods.
The carbide blade was only 3/8 wide, but had an variable tooth pattern 3 to 4 teeth per inch. Maybe the narrower width would let me tension it properly on my machine, but would it be as good as a resaw blade? Wouldn't a wider blade be more stable, and soak up more calories of heat without rising as much in temperature? Of course, the tips are where the heat is made and how well would they conduct the heat back into the body?
I thought the advise of smaller number of teeth per inch was a good one, but the folks there thought the only offering they'd seen in 2 tpi was in a 1 1/4 blade. My Delta saw says 3/4 is the max I can do. I think the 3 to 4 tooth per inch is attractive for stability reasons, but not really for my problem.
The bimetal blade was 3/4 inch, and 3 tpi. After talking it over with the counter help, I settled on the bimetal blade for a first try at my problem. It should stand up to more use and not generate as much heat... it's also a much higher temperature when it's heat treated, so it shouldn't loose temper as easily. And it was available today. :)
The bimetal was also 1/3 the price of the carbide.
I've spent the a portion of the afternoon cutting 'binga. I have made about 20 passes through this blade, and it's a real champ as far as I can tell so far. I still have a ways to go though. Hopefully I can finish cutting tomorrow and press the first one this week!
I think giving Suffolk a call is a good idea anyway, I'm interested in their blades from what I've seen posted here on Knots. And a call to Itura probably wouldn't hurt either, especially as I'm considering replacing the tension spring anyway.
Scott
Conventional wisdom is that properly sharpened, set and tensioned band saw blades of 1/2in and wider normally don't suffer from drift (i.e. twisting in cut) on bandsaws. My own experiences certainly bear this out. The HSS teeth on a bimetalic blade should be able to withstand the friction heating of deep ripping a hardwood such as Bubunga much better than a carbon steel blade, after all they were originally designed to cut metals. You really want to aim for 2 to 3tpi per inch in cut to achieve the best waste removal and reduce burning.
Good luck with the project
Scrit
Wow, Scott, sounds like you done good! Ditto the recommendation for a blade lubricant, per above. If you don't have any Dricote, you can use PAM (from the grocery store). Follow instructions on the Suffolk site:
forestgirl Another proud member of the "I Rocked With ToolDoc Club" .... :>) you can take the girl out of the forest, but you can't take the forest out of the girl ;-)
Scott, I would like to add one thing to the other posts. Use Dricote , spray on blade while running, each side. This stuff keeps blade from over heating, thus longer blade life. I use it on router bits and tablesaw blades too.Does not harm finishes.
mike
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