# Band saw guide blocks



## AxlMyk (Jun 13, 2006)

Instead of getting cool blocks or ceramic guides, I have read about using hardwood blocks that you make yourself. Cheap is good.
I have also read about people soaking those wood blocks in mineral oil and microwaving them. OK, the oil is for lubrication, but why the MW?


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## Bob N (Oct 12, 2004)

Mike,

This is one of those trick questions... Right? :jester:


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## AxlMyk (Jun 13, 2006)

Nope. :no:
I've also read that soaking the wood blocks in WD-40 works also.
Woodworking: Hardwood Bandsaw Guide Blocks - In the Woodshop


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## Bob N (Oct 12, 2004)

That is some interesting info Mike. I am curious about the microwave part though.

I have rollers on my BS, but I think the blocks are a better option in the long run, especially with the smaller blades.


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## GBM (Dec 18, 2007)

I think they are using them like Croutons in their salad...or Bacon crumbs.... 

WD 40 is not a lubricant.... better to use something that is. 
If you look at the torque tables... putting WD40 onto threads requires that the torque meter reading be increased in order to get the same pull down on the item being bolted down. I know that seems wrong.... but the engineers actually measure those things. When you put a lubricant on threads ( the standard is lightly oiled ) the torque required either stays the same ( if the substance is equivalent to oil ) or is reduced if it is slicker than standard oil in lubricating properties. 
I think a naturally oily wood should be used.... lignum vitae, etc...and then oiled in addition.


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## Ralph Barker (Dec 15, 2008)

My guess is that "nuking" the wooden blocks might "case-harden" them, that is to say, the cellular structure of the wood fiber is hardened and almost all moisture removed. The moisture could then replaced by the oil soak.


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## AxlMyk (Jun 13, 2006)

GBM said:


> WD 40 is not a lubricant.... better to use something that is.
> If you look at the torque tables... putting WD40 onto threads requires that the torque meter reading be increased in order to get the same pull down on the item being bolted down.


The WD-40 is to soak the blocks in, not the threads.

I made a few blocks out of walnut and put the ends in a small cap I sprayed WD-40 into. They soaked it up like a wick. I installed them on the saw and adjusted them right up to the blade. With the saw running I adjusted the guides forward to bury the blades in the blocks, and did a few test cuts.
Resawing a 4" piece made a straight line with no curve to the cut from top to bottom. Making circle cuts the blade held tight. The best part is there were no sparks like you might get from the steel guides.


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## Ghidrah (Oct 21, 2008)

I believe the MW is to remove moisture from the wood so that something else can take its place, like creating a sponge. Also the less moisture in the available sap means its more likely to stay put.

Still how often do you go thru cool blocks or ceramic guides?


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## GBM (Dec 18, 2007)

I was using the example of the threads because there are tables of comparisons available to show that WD40 is not a lubricant... so putting it on the wood blocks may be counter productive.... particularly if it washes away the natural oil of something like rosewood or lignum vitae.
When heating something which has moisture in it from the inside out... like a microwave does... instead of from the outside in...like a regular oven does... often causes the moisture to expand the substance or crush the cells... as with mica being turned into vermiculite. 
The fact that something gets soaked up by the wood does not necessarily mean that after it is put against the blade that is constitutes a lubricant... so it may cause more heat instead of the assumed goal of less....


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## a1tomo (Dec 3, 2008)

I,ve been told that WD-40 is more or less a dessicant. That is it will attract, or soak up moisture. The lubricating properties, I would *guess*, are probably nil or non-existant for use as cool blocks. 

To further confuse the issue, I use corian blocks as supplied by the local woodworker store. I really don't know if these are any better or worse than anything else.

Ideally, the roller bearing type would seem to be the best (nothing rolls like a ball).

That a couple of cents worth!


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## AxlMyk (Jun 13, 2006)

I'll give the blocks the test of time. So far I like them. Much cheaper than ceramic or cool blocks, which are what I was considering when I found the mention of making your own. I have 2 sets of walnut blocks. Whether WD-40 is meant to lubricate, or there is another reason, I'm still researching that. 

The roller guides are good unless you have a very thin blade, like 1/8". I also understand they compress the saw dust onto the blade. Anyway, I'm not about to shell out $150 for those.

So, I'll keep you posted on what I find.


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## Ralph Barker (Dec 15, 2008)

AxlMyk said:


> The roller guides are good unless you have a very thin blade, like 1/8". I also understand they compress the saw dust onto the blade. Anyway, I'm not about to shell out $150 for those.
> 
> So, I'll keep you posted on what I find.


Yeah, there's not much blade left behind the teeth on a 1/8" wide blade. 

FWIW, my 20" Inca came standard with roller-bearing blade guides. I haven't experienced any sawdust compression on the blade.


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## Hamlin (Dec 25, 2005)

Mike.

I believe the "nuking" of the wood after soaking is to create a seal or hardener for the wood. WD-40 isn't a lubricant at all. It does remove/repel moisture but, that's it.


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## AxlMyk (Jun 13, 2006)

I left a message for the fellow at the web site I referenced to see if he might have info on WD-40 use. I'll report here what I find out, if anything.
I figure that if nothing else, it would keep the blocks from absorbing moisture in the air.

I had a set of cherry blocks that I was soaking in mineral oil but threw them out. It seemed like a big mess to me.


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## AxlMyk (Jun 13, 2006)

Using walnut blocks soaked in WD-40, I re-sawed some 6" cherry and the cut came out dead on straight. I can turn the book matches 90º and the cuts are still flat against each other. Absolutely no cupping in the cut. This was with a 1/4" 6tpi blade.


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## derek willis (Jan 21, 2009)

I made, and presently use cool blocks made from Oak, and soaked in W.D.40 they work extremely well without any microwave technology.


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