Band saw mistake but don't know why it happened

[MilDoc]

I glued up 4 pieces of wood to make a 12" x 12" block for a BS box. I was in the process of cutting 1/4" off the back, as usual, when the blade came through the bottom 2" or so of the back face and hit the fence. I've never had this happen before, but never tried to cut a 12" block either.

I used a 3/8" 6 tooth blade as I thought the usual 3/16" 10 tooth might flex, but it happened anyway. I use a Kreg fence that is only a few inches tall and that might be the problem.

Any other suggestions on what might have gone wrong and how to do it right?

[SARGE..g-47]

I think I got what you were doing, Mildoc. Was the 12" x 12" standing on edge (12" high) and you were re-sawing 1/4" off the thick-ness?

If so, the blade drifted for whatever reason. Fence to short.. didn't attain "beam strength" with the blade (not enough tnesion).. dull blade.. guides set too loosely.. too fast a feed rate especially with that 6 tpi blade.. debri under the blade on wheel causing a bad track.. too little HP to handle a 12" deep re-saw......

The list could go on. One of the reasons I use a point fence so I can adust on the fly.

Regards...

[drumpriest]

What sarge said. I'd use a 3 tpi 1/2" blade to try and cut that, and make sure that you adjust your fence for the drift of the blade. I use that type of blade for the ripping stages and the rough outside cut of BS boxes.

[gary]

That blade should have made that cut and I'd suspect that not enough tension on it. I use a 1/4" 4 TPI for most cuts but switch to a 3/4" 3TPI for resawing.

[SARGE..g-47]

Out of curiousity Paul, what size BS do you have.. What was the tension set on for that blade and was it a standard carbon steel blade?

As pointed out, if you are going to make that cut often; investment in a larger 3 tpi blade in bi-metal (requires more tension) or the 1/2 Woodslicer from Highland Hardware here in Atlanta might be a good investment (it is thinner kerf with a 3 tpi variable tooth count and under $40). Your saw might not be enough to handle a carbide or bi-metal which requires 30,000 psi (carbide) or 25,000 psi (bi-metal) respectively. That usually requires a larger bandsaw with heavier tension springs.

If you were using 6 tpi hook or skip, that is not enough gullets to remove saw-dust on that cut. Especially if the feed rate was to high. And if you did the above, the carbon steel has a low heat barrier and will over-heat and dis-temper with that klnd of load put on it. Dulled and and virtually useless at that point.

BTW.. The Bandsaw Book by Lonnie Bird would be a good investment of $20 for most before they ever crank up a bandsaw. A better under-standing of the finickiness of the BS would allow all of us to understand what it takes to get the best results from whatever BS we have.

Regards...

[MilDoc]

I have the Ridgid BS, the blade was a Timberwolf, brand new. I tensioned it per their recommended "flutter" method. I have Bird's book and set the guides etc as he recommends. Now that you mention it, I think I was trying to feed too fast. And yes, the block is on end so I'm cutting through 12".

[SARGE..g-47]

I would have to think that the 6 tpi blade and the force feed was the culprit, Paul. Re-sawing with even a larger 3/4" or 1" blade is a slow process with 12" high stock, as it creates a vast amount of saw-dust waste. There's basically 3 speeds on re-saw.. slow.. slower and slowest. :>)

The good news is even though the results were flawed, the knowledge gained by the experience is more vaulable in the long haul than the price of the wood that was lost!

Regards...