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I have a Porter Cable Plate Jointer. The biscuits seem to fit too loose into the slots. I thought maybe my biscuits were old and dried up, so I bought new ones. Same thing. Shouldn't the biscuit fit fairly snug into the slot?
Thanks Greg
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05-30-2022, 07:18 PM
(This post was last modified: 05-30-2022, 07:19 PM by jteneyck.)
(05-30-2022, 07:00 PM)Gregor1 Wrote: I have a Porter Cable Plate Jointer. The biscuits seem to fit too loose into the slots. I thought maybe my biscuits were old and dried up, so I bought new ones. Same thing. Shouldn't the biscuit fit fairly snug into the slot?
Thanks Greg
I have some that fit loose, some just right, and others that won't go into the slot unless you whack it with a mallet. If all yours are loose then I would suspect the blade is not spinning perfectly true, either from some dirt between the blade and holding washers, or the blade or arbor is bent. But first, measure the thickness of the teeth on the blade. They should be really close to 5/32" (0.156"). If they are OK then measure the width of the slots. If they are way over 5/32" then it's time to investigate the ideas above and any others that come to mind.
John
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We bought 2 reconditioned units once. One of them had the exact same issue. Turns out, very slightly bent arbor.
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I did some test cuts this morning, and measured a few things. When I bought the new biscuits, I bought 3 different sizes. FF, 10, and 20. When I measure them, they can be anywhere from .143", to .158". I guess I need to buy a better brand of biscuits, or maybe this is common.
Greg
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(05-31-2022, 07:46 AM)Gregor1 Wrote: I did some test cuts this morning, and measured a few things. When I bought the new biscuits, I bought 3 different sizes. FF, 10, and 20. When I measure them, they can be anywhere from .143", to .158". I guess I need to buy a better brand of biscuits, or maybe this is common.
Greg
How thick are the teeth on the blade and the slots it makes? With some of the biscuits being 0,158" they should not be loose.
John
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I would think that just a little loose would be a good thing. The biscuits will expand a little when they absorb the glue.
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The thicker biscuits fit snug. I guess I will just have to check them all for fit, before gluing. I have read and heard, that biscuits add very little to the strength of an edge glued joint, and their main purpose is to align the boards. It seems to me, sloppy fitting biscuits wouldn't do that very well.
Greg
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(05-31-2022, 06:26 PM)Gregor1 Wrote: The thicker biscuits fit snug. I guess I will just have to check them all for fit, before gluing. I have read and heard, that biscuits add very little to the strength of an edge glued joint, and their main purpose is to align the boards. It seems to me, sloppy fitting biscuits wouldn't do that very well.
Greg
Don't apply glue to the biscuits. That way they will not telegraph through latter. Gust cut the slots put biscuits in it and glue it together and just get on with your life. No matter perfact you make every part of the joint you will still have a little surfacing to do after glue up. Perfectly flush glued surfaces only happen on television, and they look great after editing.
Tom
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Two things: First, try putting your biscuits into a closed container with a damp cloth. The high humidity will cause the biscuits to swell some. Maybe it will be enough.
Second, check your technique while cutting the slots. Machine vibration could cause the machine to "dance" just enough to make the slot wider. Be sure to hold it firmly to the work surface.
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(05-31-2022, 09:52 AM)sweensdv2 Wrote: I would think that just a little loose would be a good thing. The biscuits will expand a little when they absorb the glue.
Re read what Sweensdv said....they expand in the presence of moisture (glue). Tom mentioned them telegraphing through...that's because they swell. There is certainly a point where they could be too loose, but I'm not sure you have a problem. Glue up a test joint and then saw it in 1/2 after 24 hours to see how things l;ook.
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