Scoring a cut on plywood, particle board, etc.

[Packard]

Context:

I am new to using a track saw for finish cuts.  I have been using my track saw to break down sheets and making the finish cuts on the table saw.

My plan is to make the finish cuts using the track saw (Festool).  To facilitate that I have now added a TSO squaring arm and parallel guide system.

I was watching an online video over the holidays the the Festool user set the saw for a very shallow cut and made a scoring cut with the saw moving backward.  He then adjusted the depth of cut sufficient to cut through the  3/4" thick board and made the finish cut with the saw moving in the forward (conventional) direction.

He did not describe this action, but it appeared to be a standard procedure for this Festool user.

Questions:

1.  Does this work?  Does it prevent tear-out on both sides of the blade?

2.  Is it safe?  Are there any hazards associated with this type of operation?

3.  Will it damage the blade or saw?

Thanks for any advice.

Packard

 

[AlexThePalex]

Questions:

1.  Does this work?  Does it prevent tear-out on both sides of the blade?

2.  Is it safe?  Are there any hazards associated with this type of operation?

3.  Will it damage the blade or saw?

1. Yes. There's never a 100% guarantee, but it is a big improvement. 

2. Yes. I can't imagine any hazards. Not sure if backwards is really necessary, I always go forward. You can try it out.

3. Definitely not.

 

[peter halle]

As [member=5277]Alex[/member] said there may be some real life experimenting in store.

A backwards scoring cut is an option certainly, but using the Splinter guard accessory that fits into your blade shroud housing might also provide the same results with less hassle.

Peter

 

[Packard]

Thanks for the reply.  I will be starting a project using melamine clad particle board and that is prone to chipping.  I will try it on that project.

I will also try the splinter guard, though I wonder how effective it will be with the melamine.  I will try the splinter guard first.

Thanks, everyone.  And happy New Year.

 

[AstroKeith]

Context:

I am new to using a track saw for finish cuts.  I have been using my track saw to break down sheets and making the finish cuts on the table saw.

My plan is to make the finish cuts using the track saw (Festool).  To facilitate that I have now added a TSO squaring arm and parallel guide system.

I was watching an online video over the holidays the the Festool user set the saw for a very shallow cut and made a scoring cut with the saw moving backward.  He then adjusted the depth of cut sufficient to cut through the  3/4" thick board and made the finish cut with the saw moving in the forward (conventional) direction.

He did not describe this action, but it appeared to be a standard procedure for this Festool user.

Questions:

1.  Does this work?  Does it prevent tear-out on both sides of the blade?

2.  Is it safe?  Are there any hazards associated with this type of operation?

3.  Will it damage the blade or saw?

Thanks for any advice.

Packard

I recently made some bookcases with melamine faced (both sides) 20mm birch ply. All up about 100 cuts across 280mm wide boards.

I used my HKC55 saw on a short track.
I made sure the track guides the saw were adjusted for 'zero clearance', and that the track was firmly clamped to the board for each cut.

i made a first pass 1mm or so deep in the forward direction. (ie normal cutting direction)
Then finished the cut with only about 2mm of blade protruding beyond the board.
I was really careful about pushing the saw forward gently and uniformly.
I made sure the battery was always at least 50% charged.

The blade was new.

Just one chip, and I think I was pushing it askew at the end. (rushing it  [eek])

 

[AlexThePalex]

I was thinking about this backwards scoring cut, but I can not imagine how it has any bearing on the quality of the cut. You see, the blade moves at 5200 RPM, this is 87 rotations per second. This movement is so incredibly fast, that your own movement of the saw back or forth has no influence whatsoever.

 

[Svar]

I was thinking about this backwards scoring cut, but I can not imagine how it has any bearing on the quality of the cut. You see, the blade moves at 5200 RPM, this is 87 rotations per second. This movement is so incredibly fast, that your own movement of the saw back or forth has no influence whatsoever.

It makes a difference. Forward - teeth cutting up, backward - teeth cutting down (climb cut). Not sure it matters quality wise, since the angle of attack is so shallow.
On saws equipped with scoring blade they run it in reverse to the main blade.

 

[Packard]

I have made this scoring cut on the table saw with a reverse cut.  It is difficult to execute on the table saw (standing on the wrong side of the table) and registration of the blade to the original cut is not as certain as you would imagine. 

The track saw would not suffer those difficulties.  Clamped down, registration would not be an issue.

Some very expensive table saws have a scoring cutter built-in.  I don't have one of those table saws.

The track saw has accomplished what I originally planned for it--breaking down large sheets of plywood.  I am fairly confident that it will be successful in doing in one step the cutting of pieces to the assembly sizes.

I should know by this weekend.  If I fail, it will probably be because of my technique and I will be back asking for more help.

Regards,

Packard

 

[Cheese]

FWIW...Mafell has a scoring function button on the MT 55 saw. The scoring depth is 2.5 mm.

The Mafell drill is: engage the scoring button on the saw and move the saw FORWARD down the rail. Pull the saw back, release the scoring button and plunge the saw to proper depth while moving FORWARD down the rail.

No reverse scoring motions needed. I’m sure the same method will work for Festool saws because as Svar commented, the saw blade teeth contact the surface at a shallow angle.

 

[ChuckM]

I have made this scoring cut on the table saw with a reverse cut.  It is difficult to execute on the table saw (standing on the wrong side of the table) and registration of the blade to the original cut is not as certain as you would imagine.  Snip.

Regards,

Packard

How did you do that on a table saw? You installed the sawblade in reverse?

 

[Packard]

I stood on the wrong side of the table and fed it against the fence.  Worrisome because the motor is right there.  But the bigger problem forward or reverse was that I often did not get a perfect register and it would chip on the second cut anyway. 

A very shallow cut minimized the chipping, especially with plywood. But the second cut would have to be exactly on the same line and that proved to be surprisingly hit or miss. 

Even the shallow cut with the melamine clad particle board would chip (even with a zero clearance blade plate).

 

[danrush]

I routinely cut prefinished materials (melamine, mdf, foil, painted, you name it) and have found that using a "reverse" scoring cut really helps eliminate chipping. The high gloss acrylic shown in the picture seemed to be a bit unstable so I also blue taped the cut lines before scoring.  I probably use the technique on a third of my cuts.

Sent from my SM-T580 using Tapatalk

 

[ChuckM]

Snip

I also blue taped the cut lines before scoring.  I probably use the technique on a third of my cuts.

Sent from my SM-T580 using Tapatalk

I seldom need the tape given my ZCI, but when I do use it, it works every time. Alternatively, I score the sheet lightly, then raise the blade to height and rip (with a WWII 40t).

 

[Michael Kellough]

When using my ordinary tablesaw for a scoring cut I stand at the front as usual but the score is less than 2mm deep. Usually works well even with a combination blade. Forrest WW II.

 

[mike_aa]

[member=74278]Packard[/member]  You might want to experiment a bit.  I just finished cutting some utility closet shelving (to replace old pine closet boards in a 1950's house) using bullnose-edged, double-sided melamine on some type of chipboard.  I first made a shallow (1-2mm) cut with my TSC55 going forward, followed by the final cut at full depth.  No splinter guard was on the saw.  I didn't really see any edge chipping and the corner edges were so sharp that I did have to give them a quick sand to keep from getting cut during handling. 

I started with 2 foot by 8 foot material since some of the shelves were the full 24 inches in depth, but others had to be cut down to fit shallower areas.  The TSO Products GRS square and Parallel Guides definitely made quick work of it all.

Mike A.

 

[Packard]

Thanks for the replies.  I will try a couple of cuts on the panels both forward and backward to see which works better.

I am using 16" pre-drilled for the uprights and 16" shelves for the tops and bottoms and the front doors.  It should go fast.  Especially with the fact that I have only two cuts to make for the carcass.

Note:  I did need a way to align the left and right sides when cutting.  I will stack them. and then make the cut.  To keep them aligned perfectly I needed some 5mm dowels.  Four dowels inserted in the two uprights will keep them aligned while I make the cuts.

But where to find 5mm dowels?  Why, the supermarket, that's where. 

It turns out that bamboo skewers come in two sizes:  3MM and 5MM.  I bought a package of 5MM skewers--a life time supply.  I will use small pieces of these to align the two sides while making the cuts.

 

[usernumber1]

make sure the blade is clean. i tried forward / reverse had less impact - ie same thing compared to gummed up blade

 

[Lincoln]

Proper scoring cut is done 'backwards', due to the entry/exit of the teeth, which is why panel saws have the scriber running the opposite way to the main blade.
But, there's no way the maker of a hand held track saw is going to instruct you to make cuts this way.

 

[P2P]

Proper scoring cut is done 'backwards', due to the entry/exit of the teeth, which is why panel saws have the scriber running the opposite way to the main blade.
But, there's no way the maker of a hand held track saw is going to instruct you to make cuts this way.

No way in hell I'd ever push a board backwards on a table saw either!  Holy safety violation Batman! [scared]

 

[Lincoln]

Proper scoring cut is done 'backwards', due to the entry/exit of the teeth, which is why panel saws have the scriber running the opposite way to the main blade.
But, there's no way the maker of a hand held track saw is going to instruct you to make cuts this way.

No way in heck I'd ever push a board backwards on a table saw either!  Holy safety violation Batman! [scared]

Neither would I, but a panel saw runs the scorer backwards so you still feed the same way.