Are they supposed to leave a slightly scored surface, for the glue to grip better, or are the edges supposed to be real smooth?
[OP]
Contributor
Are they supposed to leave a slightly scored surface, for the glue to grip better, or are the edges supposed to be real smooth?
WoodsShop
Contributor
My Freud leaves an absolutely smooth finish.
Contributor
I use a Freud GLR blade and the results are quite smooth, with an occasional slight score mark if I stop feeding to move my hands or whatever. If you're getting a lot of scoring I'd check that your fence is parallel to the blade or just slightly toed out at the far end. A feather board or something like the Jessum table saw guides to keep board tight against the fence helps too.
--I had my patience tested. I'm negative--
The blade will leave a smooth surface on a well aligned saw. If your blade and fence are not parallel the blade will leave marks on one side or the other depending on the path deviation.
Poor alignment.
Rip Quality (1).jpg
Good alignment.
Rip Quality (2).jpg
"A hen is only an egg's way of making another egg".
– Samuel Butler
Contributor
I agree with the rest. I've owned 2 Freud glue line rip blades (one a thin kerf blade). They do leave an almost perfectly smooth finish; at least one that is essentially ready for glue up. I joint my rips anyway to get any slight imperfections out but have, on rare occasions, just glued without jointing.
Stopping the rip in the middle or allowing the board to move even a hair away from the fence during the rip can leave a saw mark. I would imagine that wobble in your blade/arbor would also cause saw marks. Then, as said before, alignment of the fence is important. Other than this, I can't think of anything that would cause saw marks.
[OP]
Contributor
OK! I'll go check the alignment right now!
how much toe out do you like to have on the fence?
WoodsShop
Originally Posted by Joe Wood
This can start a whole other conversation ;-) I set mine as close as I can get to parallel. Usually within .001 - .002". If you need a toe-out fence I would recommend a sacrificial short fence instead. I do this when required as it allllows the 'keeper' to fall away if stress release is opening the kerf. This is similar to sliders or western saws equipped with a sliding fence face for this purpose. Here's something on positioning the short fence.
Last edited by glenn bradley; 11-01-2020 at 2:45 PM.
"A hen is only an egg's way of making another egg".
– Samuel Butler
Member
Ideally none, but some people think that a few thousandths is beneficial.
Do you have a riving knife or splitter on your saw?
Still waters run deep.
[OP]
Contributor
That was it Phillip! The left side of the kerf was just hitting the splitter, bumping it off the fence a tiny bit, so I put a thin washer on one side of it,
and now I'm getting nicer cuts!
WoodsShop
Contributor
A true straight line rip saw (used for glue line rips) ,with proper blade, will leave a slight crosshatch pattern on the wood for good adhesion.
This is what was conveyed to me as proper by people who sold the machinery and people using them in factories.
This has served me well for years and many thousands of feet of glue ups.
"Only those who have the patience to do simple things perfectly will acquire the skill to do difficult things easily.”
Friedrich von Schiller (1759-1805)
"Quality means doing it right when no one is looking."
Henry Ford
Contributor
For PVA wood glue, there is no need at all for surface roughness for the glue to bond.
Contributor
Agree....and throw in the other glues. Some ADHESIVES might benefit from rough surface.
[OP]
Contributor
This is mostly 2x and up, clear wr cedar I'm usually ripping with a 12" blade.
I suspected it was meant to leave a slight scoring, I'm not too bothered with it but,
what type blade would give me an almost smooth rip??
WoodsShop
Contributor
Joe, when I use my Hammer K3 is tablesaw mode, it is done with the JessEm guides. This forces the workpiece to hug the rip fence. The lack of wandering aids hugely to a smooth cut - with just about any blade.
When I use the K3 in slider mode, it effectively does the same thing (as long as the workpiece does not move - hence the new fixture I posted here very recently) - the cut and the blade do not wander, even minutely.
Regards from Perth
Derek
Member
I've been looking at those, but I can't figure out how to have both the JessEm guides and my overhead dust collection.
Jeff.
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