Stainless exterior car trim, what metal and rods to use?

[optima21]

I think I'll be trying to make some trim parts for my Triumph Herald. Im not sure which will be the best material to use, either 316, 304 or 430 stainless sheet. if I use 316 stainless do I need to use 316 filler rods, or can I use 308, and would you be able to see the different filler rod once the welds are ground back/polished?

thanks in advance for your help/advice

 

[eSCHEn]

316 for exterior as 304 doesn't have the Molybdenum which gives 316 the better corrosion resistance to salt you'll want.

Filler same as parent metal (ie 316 for 316). I think 309 can be used but I am not 100% on what the dilution will do for corrosion resistance.

If you weld them with good pen and don't cook them then no, you can't see the welds as they're invisible.

I stand happy to be corrected by SWK

 

[Richard.]

309 is best suited to dissimilar work (steel to stainless) but it is a suitable filler for the 430 grade. Now I believe 430 would require a pre heat before welding or the joint can become brittle. I don't know a lot about this grade but afaik it also contains molybdenum. As above a 316 would be a nice choice and 316 filler readily available.

 

[eSCHEn]

Forgot to post this. This is taken a lunchtime so not the best pictures but it shows how invisible the joint is when finished (the points are constructed purely of weld). The grain is intentional. Stock is 308L and filler a mix of 308 and 316.

 

[optima21]

thanks for the replies, when I was saying using 308 in my original post, I was meaning 309 grade. looks like 316 sheet and rods are the way forwards

 

[hotrodder]

Sorted now anyway but FWIW oem stainless car trim is usually 430 stainless and none of the 3xx series make for a perfect colour match due to the nickel in them... it's not like they stand out but once polished the welds have a very slight brassy tinge to them compared to the 430

 

[langy]

I make all my trims in 316L and use 316L rod, the others can corrode, the pic below is made in 4 pieces and then welded.

 

[optima21]

thanks guys, looks like I'll be going for 316 stainless. also the existing stainless trim on the car is magnetic, so that would indicate that it could be 430 stainless (definately a ferritic grade of stainless). I guess thats no suprise with the motor trade as it would make the part cheaper to manufacture that using 316