How do you flush trim stainless sheet?

[ddruker]

I'm almost done building a U-shaped dinette out of cherry hardwood with stainless steel accents for the front of my trailer. I'm about to start on the table, and I'd like to have the tabletop be made out of stainless steel sheet, but I haven't figured out how to do the sheet metal work and would appreciate any advice.

My question is how do I flush trim a sheet of 24 gauge stainless steel for the table top - the table top is going to be 48 x 32 inches, with a substrate of 1/2" furniture grade plywood and it will have 2" or 3" radiused corners. I have aluminum t-molding to cover the edges of the table that has about a 1/16th" overlap over the top of the table - so I can be a little bit imperfect cutting if I need to, but I can't mar the surface of the stainless sheet.

If I was veneering with wood, I'd use contact adhesive to glue veneer down to the plywood substrate, rough cut with my veneer knife and then use a flush trim router bit bit to get it perfect. It would be a simple 30 minute job.

How would you handle this when the veneer is stainless steel sheet? I don't know what to try to trim it with that won't wreck the sheet and will stay within a 16th of an inch of the edge. I presume I would just burn up router bits? Would a sheet metal nibbler or power shears produce a clean enough edge?

Any other ideas for how to machine this?

[barts]

You prob. need to shear this to size. A sheet metal shop can do this with a manual shear, but they can only approximate the corners w/ a series of straight edges. I'd cut & sand a couple of pieces of MDF to the exact radius you want, and clamp those on either side of your stainless, and then file the stainless with slow strokes on a fine file to the exact shape required.

If you're set on doing it all yourself and you're w/o a stainless-capable shear, a jigsaw w/ a very fine blade (Bosch makes some nice ones) can be used at very slow speed if the stainless is tightly clamped. I'd cut it oversize and again file to the line.

Since you're in Palo Alto, TechShop has a shear that would handle this...

If you want to throw money at the problem, any modern job shop can do this on their CNC punch.

- Bart

[ddruker]

Thanks. Techshop is a great recommendation - they've got a CNC plasma cutter which looks like it would make very short work of this project. Plus how cool would it be to play with one of these.

I've got a pretty complete woodshop at home, but little in the way of metalworking tools - looks like they've got an awesome metal shop. What an amazing resource if you were doing a body restoration on an airstream.

[Wabbiteer]

I was just wish-book looking at a link from another thread and saw their stainless clad table tops. Once materials and the custom cutting is figured I wonder how their prices compare? Its a shame its a three-top minimum order, for myself I was thinking maybe two countertop pieces and a dinette top... Or buy 10 and craigslist the others!

[vswingfield]

You might check with a restaurant supply. One that builds custom tables for commercial dishwashers. They might be able to fabricate a table top for you.

Stainless is very hard to cut. It will wear the teeth off saw blades almost immediately. However, once you get the stainless top to final shape, how about leaving the plywood slightly bigger and using the flush trim bit to cut the wood to the shape of the top. Sort of reverse the process.

[ddruker]

Wabbiteer - Great link. I really like the treatments that combine the stainless top with hardwood underneath.

I am pretty sure I can build one like the one on the right myself - but I love the look of the one on the left with the wrapped edges. For sure the one on the left requires more professional tooling - for cutting and bending the sheet, welding the corners, and then grinding the corners smooth - plus the proper tooling to refinish the brushed look where you bent and ground to match the rest of the sheet.

Other thing though is both of these designs use much thicker stainless sheet than I was planning to use - I'm planning to use 24 gauge stainless sheet which weighs about 1 pound per square foot - they are using 16 gauge which weighs just more than 2 1/2 times as much.

I think I'll try to build the laminated top version, and if I don't love it, start saving to get a wrapped top fabricated somewhere locally. For the size I need, (4' x 2.5') 24 gauge stainless sheet is only about $30 - so it's not too costly of an experiment.

[chromis]

They have stainless "formica" as well..
https://www.formica.com/en/home/DNA....=PRL_DECOMETAL

or NUmetal
NuMetal « ATI ATI

Can't vouch for a table top as I was looking for a backsplash and they had some cool patterns..

[ddruker]

Vaughan - great idea, makes perfect sense.

[crisen]

Just some info on cutting stainless, I have a machine shop and we use a lot of it. Most stainless you buy is not hard at all, indeed no harder than mild steel. I won't go into the hardenable stainless steels as you just won't encounter them.

The problem with machining stainless is that it work hardens so if you 1- cut it at too high of speed or 2- too slow of a feed it will almost instantly harden at the surface where you are cutting. This is where the myth that stainless is hard and impossible to machine comes from.

For a band saw you need to be under 100 surface feet per minute, no wood cutting saw will run this slow. You might get this slow with a good saber saw.

For your 24 ga sheet you will need a very fine tooth blade, and the use of a solid cutting lube like Boelube will help.

If you get the sheet plasma cut it will have burned edges so cut oversize. You can grind to the layout lines if you take it easy (go too fast and you will also burn the edge which turn blue and destroy the appearance) with an angle grinder, then file the last little bit.

Bottom line is I would go with the recommendation to get it sheared to size, saber saw the radius corners and finish with a file.

I think reason the commercial tops are 16 ga. is it easier to fabricate especially if they are doing any welding. The only downside I can see to the 24 ga is that it might have a tendency to not lay as flat on the wood.

[rumrunner]

I would think its possible to precut as close as possible then smooth with an angle grinder or even a belt sander if done slowly and carefully.
Shear to size, nibble the corners and finish trim after glueing.
tim

[mjayjensen]

Cut a piece of scrap plywood (3/4" or so) to the exact shape required. Cut the stainless over size (3/16" or 1/4"). It can be cut any number of ways. I would use a 4" cut off wheel on a small grinder. Clamp the sainless to the plywood and use a sanding wheel on a small grinder to sand down the edge to the exact shape required.
Jay

[Wazbro]

See if you can find a shop with a water jet to cut the stainless, no heat needed.