Finish for Table Saw Sled

[John McKissick]

Winding up my first real tool making project, a customized table saw sled. Made from 3/4" sanded plywood, don't know exactly what material but pine or birch with about 7 laminations. The stuff you get at Home Depot for about $40/sheet.
Garage is unheated and pretty much uncontrolled heat and humidity in New England area

What finish would be best to keep it straight and last? Of course I want the bottom slippery (waxed).

[Bryan Lisowski]

Anything you have in the shop to use up. Otherwise shellac or poly.

[bill epstein]

My Baltic Birch sled is stored in the unheated, uninsulated closet on my deck along with my table saw and stock. No harm to anything.

I don't finish sleds or jigs for the same reason there's none on my vise jaws. I don't want raw stock to come in contact with finishes, especially oil-based.

Wax the runners and table saw top. Leave the sled alone.

[Pete Costa]

i always use a homemade oil/poly mix that's thinned with mineral spirits or turpentine for all my shop jigs and storage. Easy to apply (and reapply). Pretty sure i got it from a Fine Woodworking article my Mike Pekovich.

[andy bessette]

...Wax the runners and table saw top. Leave the sled alone.

This. No finish is the right finish.

[ChrisA Edwards]

Johnsons Paste wax on the underside and runners, nothing on top.

[glenn bradley]

Shellac ad paste wax. I re-wax every year or so. One is over 10 years old and the shellac on the bottom is still fine. I also wax my tablesaw but, the durability of the shellac on a wear surface is surprising.

[Pat Barry]

Mine is 1/2" baltic birch. Bottom is waxed and buffed. Top is polyurethane. Minnesota garage shop with space heaters. No clue why some folks say no finish. I like the bottom to be slippery. No idea why anyone thinks otherwise is better.

[Ben Schmidt]

Mine is 1/2" baltic birch. Bottom is waxed and buffed. Top is polyurethane. Minnesota garage shop with space heaters. No clue why some folks say no finish. I like the bottom to be slippery. No idea why anyone thinks otherwise is better.

Bottom slippery, yes. I think all would agree the bottom must glide across the table saw smoothly. Paste wax takes care of that. But the top side, unfinished is best - you don't want it too slick because there needs to be some friction to keep the workpiece from shifting as it is being cut.

[John McKissick]

i always use a homemade oil/poly mix that's thinned with mineral spirits or turpentine for all my shop jigs and storage. Easy to apply (and reapply). Pretty sure i got it from a Fine Woodworking article my Mike Pekovich.

Do you have any more details of this "brew"?

What exactly do you mean by "oil"? You mean oil and water based poly?

[Michael Drew]

Winding up my first real tool making project, a customized table saw sled. Made from 3/4" sanded plywood, don't know exactly what material but pine or birch with about 7 laminations. The stuff you get at Home Depot for about $40/sheet.
Garage is unheated and pretty much uncontrolled heat and humidity in New England area

What finish would be best to keep it straight and last? Of course I want the bottom slippery (waxed).

If you have not acquired the material already, you might consider using 3/4 melamine, and face it with hardwood to protect the edges. I build my sled with that over ten years ago. It is slippery, and has held up well.

[Justin Rapp]

If you have not acquired the material already, you might consider using 3/4 melamine, and face it with hardwood to protect the edges. I build my sled with that over ten years ago. It is slippery, and has held up well.

I second melamine. mine's been going for 10 or so years already. I have one for zero clearance crosscut and another with a dado cut in it.

[Pat Barry]

Bottom slippery, yes. I think all would agree the bottom must glide across the table saw smoothly. Paste wax takes care of that. But the top side, unfinished is best - you don't want it too slick because there needs to be some friction to keep the workpiece from shifting as it is being cut.
Satin finish polyurethane
Not very slippery for the top in my experience. Probably didn't need it but used it anyway.

[Pete Costa]

Do you have any more details of this "brew"?

What exactly do you mean by "oil"? You mean oil and water based poly?

Sorry John, I should have provided more info to begin with. I use an oil based polyurethane (I doubt water based would mix with the others). I combine it with either tung or linseed oil (whatever is on hand), and then mineral spirits or turpentine to thin it out. 1/3, 1/3, 1/3 is the basic mix, but don't break out the measuring cups. Eye-balling it seems to be fine. I've used this on my workbench and assembly table as well as jigs. Wears well and glue pops right off. As others have noted, you may not need anything on a sled. I did it in an attempt to seal the MDF, and then waxed the bottom to reduce friction. Probably overkill for a jig that may have a limited lifetime.

[Tom Bender]

Mine is unfinished 3/16" plywood and Basswood

427088
Weighs about 2 pounds, can be put on or off with one hand

[John McKissick]

Sorry John, I should have provided more info to begin with. I use an oil based polyurethane (I doubt water based would mix with the others). I combine it with either tung or linseed oil (whatever is on hand), and then mineral spirits or turpentine to thin it out. 1/3, 1/3, 1/3 is the basic mix, but don't break out the measuring cups. Eye-balling it seems to be fine. I've used this on my workbench and assembly table as well as jigs. Wears well and glue pops right off. As others have noted, you may not need anything on a sled. I did it in an attempt to seal the MDF, and then waxed the bottom to reduce friction. Probably overkill for a jig that may have a limited lifetime.

Thanks for the specifics. I don't keep a lot of oil based finishes on hand but your brew sounds interesting.

I ended up with two thin poly coats on the bottom and one on the rest. Going to wax the bottom too. I made it with micro-jig slots for clamps

[Jim Becker]

I don't generally put finishes on shop jigs. Many are just temporary for a specific job and those that are more permanent are just fine "totally nude". But in the rare event I do slather something on, it's either shellac or whatever else is lying about. I have older water borne finishes that I wouldn't use for a client or personal project, but for shop use, they are just fine.

[Brian Tymchak]

I don't generally put finishes on shop jigs. Many are just temporary for a specific job and those that are more permanent are just fine "totally nude". But in the rare event I do slather something on, it's either shellac or whatever else is lying about. I have older water borne finishes that I wouldn't use for a client or personal project, but for shop use, they are just fine.

Pretty much the same, but if I were to want to put a finish on my sleds, I think I would use ArmRSeal and then buff it with steel wool. Ends up smooth like a baby's b.... I would still though keep the runners waxed and the TS top polished - I use Glide Coat for all my iron surfaces.

[Justin Rapp]

Mine is unfinished 3/16" plywood and Basswood

427088
Weighs about 2 pounds, can be put on or off with one hand

And it stay's flat?

[Tom Bender]

Yes, why would it warp? This is linoleum floor underlayment. It had better stay flat!

[Pete Staehling]

I really don't see any good functional reason to put finish on mine. I won't look down on others if they choose to, but I really don't see how it makes sense from a purely functional point of view. I have on occasion rubbed some wax on the runners or even the rest of the bottom to make them slide better.

I also do put finish on some of my jigs and shop made tools but I do that for purely aesthetic reasons. I tend to do that when they are made of scraps of really nice wood. I don't claim it makes a lot of sense even then, but I sometimes can't resist :)