RAS Top Question

[Drew Pavlak]

Hello,

For those that own an RAS, how do you protect the top? I recently got a RAS from my Aunts Family, it lightly used and in really good shape. The top that was on it wasn't all that great and when looking some info up on it, I found the Craftsman Recall. Well I checked the serial number and sure enough I got a new Top and Blade Guard (for Free I should add).

Anyway, the old to was a coarse particle board type stuff. The new top is a 1" thick piece of what looks like MDF. Seeing how this just sits in the garage and I line in Michigan, I was wondering if I should put something on it. I have recently found the wonders of Johnsons Paste wax for my Table Saw, Jointer and Planer, would that work for MDF or is that a bad idea? Shouldn't have the table be slippery or would it make it swell up or something?

I have found this forum extremely helpful and thought it better to ask first than to correct my mistakes later.

Thanks,
Drew

[Fred Hargis]

The easiest way is to put a sacrificial piece on it. I use 1/4" MDF, though almost anything could be used. I pin it on, being very careful to put the pins where the blade isn't likely to hit them.

[Lee Schierer]

RAS tables are sacrificial. You want to have the tips of the blade 1/8-3/16" below the table surface when cutting (rips or cross cuts). This is done for safety reasons, making it less likely that the blade will kick back.

[Joe Scharle]

I've never used 1/4" MDF, but if I can find some I'll give it a try. But I have tried 1/4" luan and hardboard and neither stay flat very long.
I varnish or shellac (depends on what's oldest) all exposed surfaces when installing a new table and keep the top waxed. When it gets cut up, I put on another.

[Jerome Hanby]

I had to call around a lot to finally find some at a local plywood seller. When I got there they informed me they didn't sell to the public, but since they hadn't said that when I called, they would sell to me this one time. I think the next time I need some that thickness, I'll check my hardwood supplier. I bought some superior quality 3/4" MDF from them for less than the Borgs charge.

I've never used 1/4" MDF, but if I can find some I'll give it a try. But I have tried 1/4" luan and hardboard and neither stay flat very long.
I varnish or shellac (depends on what's oldest) all exposed surfaces when installing a new table and keep the top waxed. When it gets cut up, I put on another.

[Michael Prisbylla]

I use a table of two layers of 3/4" MDF with 3 3/4" x 1/8" steel bars embedded in vertical slots (3/8" + a hair in each table half) perpendicular to the blade travel. These keep the table from sagging and if done correctly on glue-up (epoxy for the bars, yellow glue for the MDF) will offer flatness to the .002" range or so. Then I use a sacrificial top of hardboard held on by LOTS of double sided tape. I'd use the 1/4" MDF for that purpose if I could find the darned stuff. The hardboard doesn't want to stay flat. I don't have a table saw, by choice, so I use my RAS for everything. This type of top (called a Mr. Sawdust table, after it's inventor, Wally Kunkel) makes a quality RAS a real precision cutting machine.

Hope my explanation was clear.

[Fred Hargis]

You might find the 1/4" MDF at HD in 2'x4' pieces, that's where I got mine....it's the only place I could find it. I think a piece was $6-7.

[John F. Snyder]

Do what Fred Hargis said. Even 1/4 inch plywood works. Do not cut into the table top that they sent you!!!

Fred: "I wish coke was still cola and a joint a bad place to be, it was back before Nixon lied to us all on TV". Great song from a great singer!

[John McClanahan]

You can always use thicker MDF, like 3/4". You will need to make a taller fence to go with it.

John

[Rick Levine]

I use what was suggested in Jon Eakes "Fine Tuning Your Radial Arm Saw" book. There are a great many excellent tips in it. Buy it if you can find a copy.

"Now we want to cover the table “base” with a disposable working surface. This way the table base never needs to be changed again. Figure 3-1 shows a ¼” plywood cover placed over the front portion of the table. Quality finished plywood, not shop grade plywood, is best for this application. Both sides should be smooth and free from defects to fit properly to the table base and to provide a smooth working surface. Masonite is not recommended here because it is unnecessarily hard on saw blades and moves too much with moisture changes. It should fit both sides and the front of the table exactly. It should fall 1/16th to 1/8th of an inch short of the fence as seen in the photograph. This is an important little detail as without the small gap, slivers of wood are constantly catching between the fence and table holding the workpiece away from the fence in an untrue fashion. It is bothersome and often difficult to remove these slivers, sometimes requiring loosening of the fence. The small gap between the table cover and the fence eliminates all of that. Splinters that collect there can be blown or brushed away easily whenever necessary as they don’t jam into the crack.
No effort is made to cover the back side of the table, nor even the 1-1/2” spacer. There are two reasons for this. First of all, with the back table ¼” lower than the front table we can drop the blade 1/8” into the table cover for an ordinary cut, but it still floats above the back table to allow swinging into miter positions without having to lift the blade. When the fence is moved back to either rear position, we are almost always ripping quite far forward on the front table and hence our workpiece is well supported near the blade. The fact that the back portion of the table is ¼” lower will rarely effect the cut. If it is a problem in a special case, a ¼” filler can be set in for that job.
I attach the table cover with small brass tacks (brass so that if they are struck by the blade there is no damage and no spark) together with a conservative blob of rubber cement (you can buy it at a stationery store) at the location of each tack and all along the rear line of the table cover. Do not use contact cement as it is too strong. The glue is there to assure that the cover stays down and flat, that no sawdust sneaks under it at the fence, but leaving it relatively easy to pry up and change when it gets too chewed up and a new cover is needed. The tacks are there to hold the cover down tight while the glue dries. (If you have other means of pressing the two pieces together you can skip the tacks altogether.) See Figure 3-2 for an idea of the placement of the tacks so that they avoid the primary zones of saw cutting. Make sure to counter sink the tacks just below the surface of the cover."

[Basil Rathbone]

RAS tables are sacrificial. You want to have the tips of the blade 1/8-3/16" below the table surface when cutting (rips or cross cuts). This is done for safety reasons, making it less likely that the blade will kick back.

Always use a sacrificial top. Cut into it about 1/16th to 1/8th so you can complete the cut. With use, the kerf will widen out until you decide it is time to replace the sacrificial top.

The fence is also sacrificial, so replace it as often as needed also, so you are using a fresh cut in it to line your workpiece up.

[Mike Wilkins]

I no longer have a RAS, but when I did, I made a table with a replaceable insert that followed the blade path. This insert was just a 1/4" deep dado plowed into a piece of Melamine; the insert was 1/4" plywood with countersunk screws on its length. When this insert was chewed up and no longer offered zero-clearance support, just pop the screws out and replace it with a new piece of 1/4" ply.