Making custom trim

[chevynut]

I need to make some custom interior trim and I'm not sure which direction to go with it.

The pieces are 3/16" thick, and 1/2" and 3/4" wide. The two 1/2" pieces are about 40" long and the two 3/4" pieces are about 18" long. There's also a few short 1/2" wide pieces.

My choices are steel, stainless, and aluminum. I want it to be shiny, and STAY shiny so I think Aluminum is out for me. Plus I want to attach some studs to the backside which is difficult with aluminum. It's not really thick enough to thread.

So that leaves steel and stainless steel. The pieces will be ball milled down the center. That shouldn't be hard to do with steel. Using 304 stainless would make it very difficult to machine, and most shops don't like to mess with it. So I can use 303 stainless which machines well and polishes nicely. However, it's almost THREE TIMES the price of 304, which is already almost twice the cost of steel. And it's not easy to find in the dimensions I need. I don't want to pay for more machining than I need to.

I plan to silver solder studs to the backside. If I use steel I would have it chromed.

I am thinking the cost of chroming the steel is WAY more than the additional cost of the stainless. I can polish the stainless myself, so I don't have to pay the $25 per foot most polishers charge. Even if I did I think the stainless still comes out less expensive.

Can you think of any reason not to use stainless? Any opinons or experiences machining 304? I have found it to be okay to turn on a lathe, but not sure about ball-milling. Is the additional cost of 303 worth it? I found it once but don't even know if I can find it again in a 3/16" thick flat bar.

[Rick_L]

I don't think there is as big a difference as you make it to be with the 304 vs. 303. Get the spindle speed and table feed right, and it won't be a problem. Tip: if you see a burr or a worse finish on one side of the cut relative to the other, make the final cut in 2 passes, cutting one side at a time by making the last cut .005" offset, and in the opposite direction.

The other thing you could do is consider using brass and plating that.

[chevynut]

I hadn't thought of brass but it looks like it's about somewhere between 304 and 303 stainless in terms of cost. However, if I'm going to plate it I would think I'd want to just use plain steel since it's cheap. It's probably no cheaper to plate either one.

Since I can polish it myself I'm leaning toward using the stainless. I guess I should go talk to the machine shop about which material they prefer to cut. I have no idea what they'll charge me to do the milling. The tolerances aren't very tight.

[Rick_L]

I don't know how many pieces you want to make or how long, but maybe the best first step is just to make a short sample, say 12" or 18" long.

You could demo your stud fastening and your polishing on that sample too.

[Run-em]

I can't remember the name, but there is a company that produces several types/shapes of trim = both for exterior and interior use. They serve the hot rod / show car industry. I shall keep looking on the web and report back their name, if and when it is found.

Good luck, my friend.

[NickP]

40" will be the issue. Holding it in place, given the size listed will be the next issue depending upon the relief size and the depth. Noy many shops have a table length of the size needed to accomodate that length.

[MP&C]

Use 22 ga sheet instead of solid SS, then some trim clips...

https://www.youtube.com/watch?v=QSSlAxS6mm4

[NickP]

I hadn't thought of brass but it looks like it's about somewhere between 304 and 303 stainless in terms of cost. However, if I'm going to plate it I would think I'd want to just use plain steel since it's cheap. It's probably no cheaper to plate either one.

Since I can polish it myself I'm leaning toward using the stainless. I guess I should go talk to the machine shop about which material they prefer to cut. I have no idea what they'll charge me to do the milling. The tolerances aren't very tight.

http://www.speedymetals.com/pc-971-8257-316-x-34-303-stainless-steel-hot-rolled-annealed-pickled.aspx

[NickP]

Use 22 ga sheet instead of solid SS, then some trim clips...

https://www.youtube.com/watch?v=QSSlAxS6mm4

A MASTER!

[Hawaiian]

A MASTER!

I know you are looking for stainless but this could be something you could use since it's for the inside of the car.
Kirist Kustom or Clayton Machine

[NickP]

Clayton has some really nice stuff. Decent price too. Thanks for reminding me of them - Aloha and Merry Christmas to you Calvin!

[chevynut]

Thanks guys. I have looked at Krist Customs and have bought some interior parts from them. Their trim is 3/8" x 5/16" which would work, I suppose, but it's aluminum which I don't like. Plus it's pretty expensive for material that's not exactly what I want. Same with Clayton's which is where my interior door handles came from. They make some nice stuff, but again it's aluminum, only 1/4"x 1/4" and not really what I want.

This trim is for my door panels and other interior areas. Where the long piece goes the panel is 1 1/2" to almost 2" thick. I thought about using my stock stainless 56 door panel trim that I still have but don't know how to attach it and it's too long. I thought it would be easier to start from scratch.

I've looked at Discount Steel, Online Metals, and Speedy Metals. I've bought from Discount quite a bit, and they have 304 flat bar but no 303. Online Metals has either 304 or 303 in the sizes I want. Speedy Metals has the 303 stainless in 3/4" width, but not 1/2". Discount just so happens to be having a 24% off sale today until midnight so I may just order some 304 from there.

I know 40" is long but none of this is very precision work. I want it ball-milled down the center to make it concave. I think they could put the end in the vise, cut it, and move it over and cut again until they reach the other end. I think they can cut 6-8" at a time depending on their vise. Or they could clamp it directly to the table and cut it. I've even see machinists use double-sided tape to tape the part to the milling table. As long as they set it up right it should work fine. I can sand and polish out any small defects. I need to talk to a machine shop about doing this because I don't have a mill. This may end up resulting in me buying one like I did my lathe when they quoted me for turning a few parts for me. LOL! :)

[chevynut]

Just placed my order with Discount Steel....$53 for 15 feet of 1/2" wide and 5 feet of 3/4" wide flat 304 SS bar. If anyone needs to order some specialty metal you can't find locally, the 24% off code today is JOLLY.

Now I hope I can get it machined for a reasonable price. If not I guess I'll borrow a mill and do it myself....as usual. :)