how to deal with rust pits in my Unisaw cabinet

[Michael Weber]

Refinishing my old Unisaw cabinet. There was some rust pitting in areas. I've sanded down to bare metal in those areas but the pitting remains. Do I need to continue sanding until the pits are gone or can they be filled with something (bondo/epoxy) and sanded smooth before painting? If they can just be filled then do I need to treat the pitted area before priming with Rust-Oleum gray primer? Thanks, Mike

[Art Mann]

You can probably fill the pits with a high build primer instead of the Rustoleum. Just shoot a couple of coats with sanding in between. I would use bondo as a last resort.

[David C. Roseman]

I wouldn't use Bondo body filler for such fine work. High-build primer will work, as Art says. But if the pits are at all deep, it will take multiple coats and a lot of careful sanding as you go. I'd suggest trying Bondo's automotive glazing and spot putty.

http://www.worldpaintsupply.com/bondo-glazing-and-spot-putty-4-5-oz/

Comes in a tube as a one-part compound that fills and fairs easily, dries in a few minutes. Skim it on with a flexible plastic applicator. You can make one from a piece of a plastic gallon milk container.

David

[Stephen Cherry]

I would recomend going to the auto body place and getting ppg metal cleaner and metal conditioner. These, if you follow the instructions very carefully, will eat the rust, and leave a coating on the machine. If you want to spend a little money, you could follow this up with ppg dp epoxy primer. Over this could go a filler, something like bondo, then another coat or two of ppg dp epoxy, so that the filler is sealed in by the primer.

Over that you can use anything, with the future rust controlled by the epoxy. Epoxy needs some sort of top coat for UV resistance.

[Mike Schuch]

My father bought a Powermatic 71 12" cabinet saw from a window manufacture for $1. It had wings welded to the cabinet that formed a mobile base. After cutting the wings off with a grinding wheel and stripping the rust with a metal brush I used Bondo as a filler on the cabinet then sanded before painting with Powermatic green. The saw now looks like new. 3 years now and I haven't had any problem with the areas I used Bondo on, or any of the other areas for that matter.

I have made many shop shelves out of jointed and planed 2x4's frames with plywood inset in the frames to form the shelves. I use Bondo to fill in the cracks between the plywood and the frames. 10 years now and the shelves look like new... but covered in saw dust. I use these shelves for storing all my hand power tools and pneumatic tools. For me Bondo has always done an awesome job! I have never has a problem with it cracking or chipping.

[Bill Geibe]

You want spot putty (or glazing and spot putty, depending who you talk to). That's exactly what it's used for - small imperfections before the paint goes on. You can put it on over primer. It's kind of like a thick primer that you spread on and then sand smooth. Like spackling compound but for painted metal. Car body guys use it all the time.

http://www.amazon.com/Bondo-Glazing-Spot-Putty-1lb/dp/B0002JM8OK/ref=sr_1_3?s=automotive&ie=UTF8&qid=1375310179&sr=1-3&keywords=Glazing+and+Spot+Putty

267650

I used it on my Unisaw cabinet with Rustoleum paint and was happy with how it came out.

267652

Bill

[Michael Weber]

Thanks everYone for the suggestions and recommendation. Probably should have mentioned its going to strictly be a rattle can job. I'll get a tube of the spot putty. I'll be using Rust-Oleum dark machine gray. Not nearly as blue as the finish on it now but whatcha gonna do?

[Bill Geibe]

Michael,

Mine in the picture is a rattle can job. I used Rustoleum Smoke Gray. It was a closer match to the original paint than the darker Machine Gray. Rockwell/Delta used many shades of gray, though, and I know a lot of guys use the paint you've chosen. The Smoke Gray has more blue in it.

Reminds me of a story I heard about a guy who walked into a shop of all original Delta/Rockwell equipment. Every tool was a slightly different shade of gray.

The Rustoleum dries a bit slow and I found out the hard way that if you put it on too heavy it will wrinkle as it dries. the trick is to spray the final coats on wet, but not too wet. Krylon dries quick but I figured the Rustoleum would be more durable.

Incidentally, I've had the saw back in operation for about two years and the paint has held up fine. If you want to see the (lengthy) restoration process it's here: http://owwm.org/viewtopic.php?f=1&t=94388

Bill

[David C. Roseman]

[snip]

Reminds me of a story I heard about a guy who walked into a shop of all original Delta/Rockwell equipment. Every tool was a slightly different shade of gray.

[snip]



Bill, I was waiting for the punch line! Maybe this is a new marketing opportunity for Delta, apologies to E.L. James. "Turn up the excitement in your workshop with Fifty Shades of Gray."

Very nice refurbishing job, BTW.

David

[Myk Rian]

Reminds me of a story I heard about a guy who walked into a shop of all original Delta/Rockwell equipment. Every tool was a slightly different shade of gray.
That's the norm. There didn't seem to be much QC as to paint color.

[Matt Meiser]

I've never really worried about it, but I've always use a thick oil-base paint like Sherwin-Williams industrial enamel or a Rust-O-Leum type paint with Valspar Hardener from Tractor Supply added. The thick paint flows out and hides any minor imperfections.

[Bruce Wrenn]

I've never really worried about it, but I've always use a thick oil-base paint like Sherwin-Williams industrial enamel or a Rust-O-Leum type paint with Valspar Hardener from Tractor Supply added. The thick paint flows out and hides any minor imperfections.Rust-O-Leum is a Valspar product now.

[Bill ThompsonNM]

Rust-O-Leum is a Valspar product now.
Actually no, valspar has a rust preventative spray paint but Rustoleum is a wholly owned subsidiary of RPM international who also owns such products as Watco and Zinser (and about 30 other brands you'll probably recognize )