Guide Rail - How to Minimize Tearout?

[Bugsysiegals]

I’ve been noticing more tear out than I’d like to see while using the track saw.  Thankfully it's just drawer box bottoms which will be hidden in the dado's but I need to resolve this issue as this would be unacceptable on exterior cabinet panels.

I've noticed a decent gap between the blade and splinter guard and that it appears jagged and not straight ... is this expected?  Would forcing the cut to fast or a dull blade cause some deflection of the blade?  I checked the side to side play of the saw and while it didn't appear to move I could see the Black plastic tabs which protrude through the top of the saw by the side to side adjustment knob moving a tiny bit.  I tightened the adjustment knobs until these no longer move and the saw is now a bit stiff but a small price to pay for eliminating any side to side deflection.

I recently readjusted the blade angle on the TS 55 which wasn't that far out of square and I wouldn't expect that to be the cause of this uneven/jagged gap which seems larger than from some small blade bevel angle adjustment?

Can the splinter guard be removed, moved out ~2mm, re-applied, and re-cut rather than buying an entirely new one which I'd need to do for the FS 1080 I've shown below as well as likely my FS 3000 and FS 1400?

View attachment 1 View attachment 2

 

[Packard]

I recently had terrible tearout on plywood I bought from Lowes.  I used the same setup to cut some other plywood without that tearout. 

I suspect that the veneer surface was overly thin and perhaps not well-glued to the substrate. 

Have you tested for tearout on other grades of plywood?

 

[afish]

I would get a fresh saw splinter guard (green piece) as these are a wearable part and if the saw was cutting on a bevel it may have widened it some extra amount.  A newly sharpened or fresh blade properly designed for the task and move replace the splinter strip on the rail.  Not sure if the strip can be successfully moved or not.  I only had one festool track (LR32) and never made one cut with it but that dang thing was always trying to come off even after only a couple months.  Im in S. Florida so the heat might have been an issue but the rubber on my 2 Makita rails is still tight as can be after a couple years.  That silicone type strip seems to not want to stick and once it lets go it never seems to stick as good again.  If it was me I think I would replace it and try the makita rubber on the festool track.  Not sure if anyone has tried that.  Doing those three things will get you the best possible results that you are going to get from the saw the rest will be the result of technique. 

 

[afish]

Also make sure your blade is running parallel to the track.  I think peter parfitt did a video on tuning up the festool track saw.  I checked mine and it was indeed off.

 

[Michael Kellough]

I’m still using the old black rubber splinter guards. I can and do move them out and re-trim but I don’t know about the “clear” strips. Since they tend to fall off on their own the adhesive might not allow reusing.

In the meantime you can pre-score the ply, especially helpful when cross cutting. With the guide rail clamped, set the depth of cut so you only cut a mm. Much less likely to pull the veneer up. Then set depth of cut to suit the material thickness and complete.

Another option is to cut the ply with the good side down. Only practical if you really have got the bevel set to 90*.

 

[woodferret]

That furry grain...  aspen ply?  If so, score cut first.  It's just that wood.

 

[Bugsysiegals]

This is 3/8” Baltic Birch plywood which I’ve noticed seems to only tear in one direction, perhaps cross cutting, and is happening on the bottom of the board while on the MFT/3.  I would’ve figured the table would prevent this and tear out would happen on the top ... is it normal for the tear out to be on the bottom?  Maybe I need to move the guide and start a new slot?

FWIW - the blade never reaches the Green piece on the side of the saw until you plunge more than 1/2” which doesn’t happen on 3/8” plywood.

 

[sancho57]

when was the last time you cleaned/ sharpened your blade

 

[Bugsysiegals]

I just cleaned the blade a week ago when I re-calibrated it for square. I’ve never had the blade sharpened but have only used it to break down 8x 4x8 3/4 Maple plywood sheets, 5x 5x5 5/8” BB sheets, and 2x 5x5 3/8” BB sheets.  This seems like only a little to me as it’s only 4 shop cabinets ... how often should a blade be resharpened?

 

[sadcrg@comcast.net]

Is the saw depth sufficient to completely clear the plywood on the back side? I have cut with my TS75 and had the depth set to slightly more than the thickness of the plywood. The resulting cut produced a bottom (backside) cut that had similar tearout. My theory was that as the blade was about to break through the plywood, the shallow depth of cut was "pushing" the wood fibers before actually breaking (cutting) them. I adjusted the depth of cut deeper and it corrected the problem in my situation.

 

[Bugsysiegals]

I was probably 1mm deeper than the plywood as I didn’t want to cut to deep into the MFT table.

To your point ... I believe I recall reading that having the teeth just above the surface of wood on a table saw results in the blade pushing the fibers parallel with the surface resulting in more tear out than having the blade gullet at the surface which is coming down on the surface and pushing fibers into the center resulting in less tear out.

 

[mino]

I’m still using the old black rubber splinter guards.

1) re-calibrate your saw, the blade must be parallel with the guide
2) change/refresh the splinted guard
3) consider a new blade, but you have an old splinter guard, so that is what is the most likely cause

Before applying new guard, make sure to remove any glue residue from the rail. In addition of being new, the now sold "clear" splinter guard is from a harder material so while is harder to see it works better in the anti-splinter role as applies more pressure closer to the cut line.

Do not be afraid of glue on the new one. The "clear" one has reinforcements in the glue layer, so the glue should "stay with the plastic" instead of leaving the rail dirty when you are removing it for a replacement.