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Table Saw Throat

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Forum topic by Maynard posted 06-12-2009 07:12 AM 864 views 0 times favorited 11 replies Add to Favorites Watch
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Maynard

36 posts in 2028 days


06-12-2009 07:12 AM

Many decades ago, I was constantly expriencing tearout on my plywood cross cuts on my Powermatic Table saw. Then an old cabinet maker who had several fingers missing, thus proving (in the 70’s era) he was certainly an experienced cabinet man, taught me this

If you use a table saw much, you will soon wear out the Throat. This is the part that you remove to change blades. The Throat is worn out when the kerf in it is not exactly the same width as the teeth on the blade. If you do different width dados on the saw, you need a throat for each size. If the Kerf in the throat is much wider than the teeth on the blade(s), you will experience tear-out.
Now, it does not seem as bad as it did in the old days, with 1/8” to 3/16” wide carbine teeth on really heavy blades, but the problem will still exist if the kerf in throat gets too wide.
A new throat can easily be made by using the old throad as a guide to cut a new one from a 3/8” thick plywood scrap.
After you band saw, or in some way cut the outside perimeter, you now place it in the saw with the blade totally retracted.
If the new throat sits too low, and it should, locate the 4 small feet that it is sitting on. Mark their location and place a small flat head screw on the bottom of the throat where it thouches these little feet.
Place the new throat on the saw and adjust each screw until it is exactly flush with the table. If anything, place it 1/64” above the surface of the table and sand down the front edge so that the panel will slide over it and not bump into it.
Now place the fence over the new throat making sure it will not me hit by the blade and slowly raise the blade while you hold the other long edge of the throat down with a piece of scrap wood.
I would suggest that you cut severa throats at one time and keep them aroung when you need a new one or change from one dado blade to a smaller one.
Hope all this is clear, and look forward to your comments.
Larry


11 replies so far

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TopamaxSurvivor

15029 posts in 2400 days


#1 posted 06-12-2009 07:37 AM

Yup, we talked about this not to long ago. I use epoxy to make my little feet to hold it flush. Same way you bed a rifle barrel and action. Use paste wax and wax the metal around where the throat sits real well or you will epoxy the plate in permanently :-)) Mix up a little epoxy, put it on the plate and set it flush. Come back in an hour or two or the next day and do another. Run your saw blade up and you’re set. Not messing with little feet or adjusting.

-- "some old things are lovely, warm still with life ... of the forgotten men who made them." - D.H. Lawrence

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lew

10130 posts in 2479 days


#2 posted 06-12-2009 02:48 PM

I did a process similar to Topa’s except used Hot Melt Glue. It sticks to the wood but not the little metal “rests” in the throat area. I sets up quicker than epoxy.

-- Lew- Time traveler. Purveyor of the Universe's finest custom rolling pins.

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patron

13146 posts in 2065 days


#3 posted 06-12-2009 04:43 PM

i buy good 1/8” blades and keep them sharp !
also change them for the cut required .
i can use the 1/8 ” in my calculations ,
and the stiffer blade doesnt whip as much .

-- david - only thru kindness can this world be whole . If we don't succeed we run the risk of failure. Dan Quayle

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SnowyRiver

51450 posts in 2204 days


#4 posted 06-12-2009 09:42 PM

I agree with patron. I think a lot of tear-out problems relate to a dull blade. I have never used zero clearance throat plates. I use the metal Powermatic plates. I always use sharp blades and have never had a problem. I do use a thin kerf blade most of the time. I always use the blade stabilizer as well.

-- Wayne - Plymouth MN

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Maynard

36 posts in 2028 days


#5 posted 06-13-2009 04:50 AM

What would you do with a dado set?
Larry

View SnowyRiver's profile

SnowyRiver

51450 posts in 2204 days


#6 posted 06-13-2009 12:26 PM

I have a steel dado insert. It of course, has a fixed opening that I use for all combinations of width, but the dado blades (Forrest) that I have I keep razor sharp and it works fine.

-- Wayne - Plymouth MN

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Maynard

36 posts in 2028 days


#7 posted 06-13-2009 03:57 PM

Do you sharpen them your self, and if not how much does it cost to resharpen.

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SnowyRiver

51450 posts in 2204 days


#8 posted 06-13-2009 06:27 PM

No, I dont. I have mostly Forrest blades so I send them back to them for sharpening. It runs about $30 for a 10” 80T blade and about $60 for the dado.

-- Wayne - Plymouth MN

View stefang's profile

stefang

13530 posts in 2058 days


#9 posted 06-13-2009 07:00 PM

Sharp blades are probably the best way to make a clean cut, but if you are like me and don’t have your blades sharpened often or don’t have more than one, then a zero clearance throat plate might be just the thing. Bob’s idea with the epoxy works well. Another way to do it is to drill holes in the 4 corners of your throat plate and cut some threads in them for set screws. This way you can make minute adjustments from the top with an allen wrench. I guess there must be a million ways to do this.

-- Mike, an American living in Norway.

View Bill White's profile

Bill White

3541 posts in 2685 days


#10 posted 06-13-2009 10:13 PM

Zero clearance is good, sharp blades are great, both are a combo hard to beat.
Some woods will tear out regardless. Poplar is one of ‘em. Using some paint grade poplar on a trim job, and have a newly sharpened 80 tooth blade on the MS. Still get some fuzz on the back side of the cut.
Bill

-- bill@magraphics.us

View James's profile

James

162 posts in 2005 days


#11 posted 07-05-2009 12:54 AM

when crosscutting i put some masking tape over the cut line, seems to help out quite a bit

-- James, Bluffton, IN

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