cutting a shape out of stainless steel

I have a fixture in the bathroom which has some chrome plated steel end caps that tend to rust. (There is an edge that is kind of rough and the rust seems to start in the pits of this rough corner. I have a suspicion that this manufacturing flaw is the cause of the rust problem.)

In any case, I thought the simplest permanent solution would be to replace these chromed plated pieces with stainless steel. The pieces in question are flat pieces with two screw holes in them. I have no experience working metal, and am wondering if I'm likely to run into any unexpected complications. My plan is to buy a sheet of stainless steel from McMaster-Carr of the appropriate thickness, use my woodcutting bandsaw (fitted with a suitable blade for metal cutting) or maybe my jigsaw to cut the form out maybe a tiny bit oversized, use files to get it to the exact shape required, use sand paper to make the edges pretty, and to use my drill press to drill mounting holes with countersinks.

Is there anything wrong with this plan or anything that should be done differently? The parts are about 2" x 4" with a curved shape and I will need four of them.

I guess my concerns/questions are:

1) Is it hard to cut and drill stainless steel? Does it matter what kind I get, both in terms of corrosion resistance in the bathroom and ease of machining?

2) McMaster Carr lists stainless steel with a variety of different finishes that are given numbers like "Mirror Polish #8" or "Brushed Finish #4". What do those numbers mean? I have sand paper on hand going up to 1500 grit and some abrasive sheets in 5 and 0.5 micron. But I would like to know how to match the abrasive I use to polish my cut edges to the finish that comes from the manufacturer. Is it reasonable to use my sandpaper for this task, or is there some other abrasive that will be considerably better/easier to use, etc?

3) Will it be OK to use a 14" wood cutting band saw (fitted with a suitable metal cutting blade) for this application.
Reply to
adrian
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For your bathroom 304 or 316.These alloys will also look the most like chrome when polished. Get the polished sheet. But you idea of cutting this stainless steel with your wood cutting bandsaw won't work. The stainless is much too tough for the speeds that the wood saw runs at. For a carbon steel blade the blade SFPM (Surface Speed Per Minute) should be about 60. Your wood cutting saw runs way faster than that. The blade will be ruined almost instantly. A hack saw, with cutting oil, will work. Don't push the blade too fast. But do keep constant pressure on the blade. 304 stainless will work harden and then the hacksaw blade will dull. If you can, back up the sheet with a piece of wood so that it can't flex during cutting. After cutting the edges should be finished first with a file unless you have a belt sander. The final finish, to be truly polished, will have to be done with a buffer. I wonder if maybe getting new pieces and clear coating them with an epoxy paint maght be easier. Oh, and you are correct about the manufacturing defect causing the rust. ERS

Reply to
Eric R Snow

Your woodworking band saw will not run slow enough. A variable speed saber saw might work at its slowest speed. You'll nee lots of blades. The problem with SS is that it work hardens and then becomes almost impossible to cut with a saw.

Try some sheet metal shops in your area to see if they can or will shear the metal (it needs to be thin). A better possibility is a welding shop that has a plasma cutter. You could clean the edges with a disk sander.

JMiller

Reply to
<jamw42

I would do this job with a disc grinder and some of those very thin cutting discs. They use the same technique on the TV series "American Chopper" when they are fabricating special pieces for their motorcycles. I have cut metal like this and it works great.

One word of warning though, a friend of mine lit his crotch on fire while doing this. He was wearing nylon/polyester cargo pants. Be very careful where the sparks are going when cutting with a disc grinder and for god's sake, don't wear any synthetic clothing, it burns like crazy. BTW - he didn't suffer any damage, just had to replace the pants.

------------------------------------------------------------ snipped-for-privacy@cam.cornell.edu Jan 27, 7:41 am

I have a fixture in the bathroom which has some chrome plated steel end caps that tend to rust. (There is an edge that is kind of rough and the rust seems to start in the pits of this rough corner. I have a suspicion that this manufacturing flaw is the cause of the rust problem.)

In any case, I thought the simplest permanent solution would be to replace these chromed plated pieces with stainless steel. The pieces in question are flat pieces with two screw holes in them. I have no experience working metal, and am wondering if I'm likely to run into any unexpected complications. My plan is to buy a sheet of stainless steel from McMaster-Carr of the appropriate thickness, use my woodcutting bandsaw (fitted with a suitable blade for metal cutting) or maybe my jigsaw to cut the form out maybe a tiny bit oversized, use files to get it to the exact shape required, use sand paper to make the edges pretty, and to use my drill press to drill mounting holes with countersinks.

Is there anything wrong with this plan or anything that should be done differently? The parts are about 2" x 4" with a curved shape and I will need four of them.

I guess my concerns/questions are:

1) Is it hard to cut and drill stainless steel? Does it matter what kind I get, both in terms of corrosion resistance in the bathroom and ease of machining?

2) McMaster Carr lists stainless steel with a variety of different finishes that are given numbers like "Mirror Polish #8" or "Brushed Finish #4". What do those numbers mean? I have sand paper on hand going up to 1500 grit and some abrasive sheets in 5 and 0.5 micron. But I would like to know how to match the abrasive I use to polish my cut edges to the finish that comes from the manufacturer. Is it reasonable to use my sandpaper for this task, or is there some other abrasive that will be considerably better/easier to use, etc?

3) Will it be OK to use a 14" wood cutting band saw (fitted with a suitable metal cutting blade) for this application.
Reply to
Buy_Sell

I seem to recall that my wood cutting bandsaw runs at 1600/3200 sfpm (it's got two speeds). In any case, way beyond 60.

I saw at McMaster Carr a "carbide grit rodsaw" blade that was listed as able to cut stainless steel. Would something like that be appropriate? Is it going to take a century to make these cuts? (I'm not sure what my thickness is. I'm guessing somewhere around 1/16 inch.) A standard hacksaw blade would be too wide to cut the curves.

I notice that most jigsaw blades are listed as suitable for nonferrous metals. Is stainless steel considered ferrous (I mean, magnets don't stick to it).

I persuaded the manufacturer to give me new parts (for the second, but final time), so I could try treating either the whole thing or just the suspicious areas where the rough spots are on the new parts and hope it helps, and avoid messing around with the stainless steel. It seems that getting a uniform coating of epoxy might be tricky, though. The offending area is an edge. Is this something that you brush on? Would it be unobtrusive? Can you point me to an example product? (I've seen epoxy paints for floors, but they are generally opaque.)

Reply to
adrian

By "disk grinder" do you mean something like a dremel tool with a little cutting disk? Or something else, maybe a cutting disk in a hand drill, since everybody seems to be saying slow is good?

Reply to
adrian

I saw some carbide grit saber saw blades and also some high speed steel saber saw blades that were specifically listed for stainless steel. Would these work well, or would I still find that I'd need lots of blades? (I do have variable speed.)

Can shearing produce curves?

Reply to
adrian

The right knid of shear can. The carbide grit blades would cut the SS, but slowly. The paint should be spray paint. Look for clear caot Krylon. I think it's available in epoxy clear coat. ERS

Reply to
Eric R Snow

Slow is good for toothed blades, or drill bits. But not for abrasives. What they are suggesting is using a 4 1/2" angle grinder, like you use to clean up welds. You use a very thin, like .040, abrasive cut off wheel in it, and you literally burn thru the stainless.

This will work, as long as there are no concave curves. Convex curves, or straight lines are pretty easy to cut, although noisy and sparks flying everywhere.

But if I was you, I would find someone with a plasma cutter to cut these out for you. Then you can clean em up, and drill your holes.

Reply to
rniemi

Are you sure that there is clear epoxy spray paint? I have hunted around online and I have found a clear epoxy coating in bottles (which may be suitable), and I have found Krylon Epoxy Appliance paint in three opaque colors, but no clear epoxy spray paint. Would some nonepoxy clear coating work? (I know that the last time I used spray paint they wanted you to sand the surface first and then use a primer, which wouldn't work too well for me.)

My shape is concave. If I wanted to hire someone with a plasma cutter what would I want to look up in the phone book to find such a person? I mean, does every machine shop have a plasma cutter? (Are there any mail order machinist services that might be able to do this for me?)

Nobody has said anything about the drilling part of this task. Is the drilling straight forward? If I just use an ordinary twist drill bit and lube with some kind of grease? Any kind of countersink?

Reply to
adrian

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