View Full Version : Metal Finishing Question

05-13-2011, 02:46 PM
After making a part of steel plate it needs to be finished. I haven't decided yet whether to chrome or powder coat it but in either process I am up against the same issue. During the manufacturing process some small marks (indentations) were made in the material. Rather than grind or polish the entire part to the level of the "dings" what can be used to fill them that will still stand up to either the temperature of the powder coating oven or the electro- chemical process of plating? I know car bumpers can be straightened and rechromed, what is used in that process to fill small dents, gashes etc. during that process?
I was considering brazing, mig welding and soldering and then grinding off the areas to match the surrounding surfaces. Has anyone any experience with this method?

05-13-2011, 03:26 PM
Soldering is a now go since the lead melting point is really low, not sure how the finish will turn out if you fill and chrome but powder coat should be ok for braze or tig.
I read on here I think it was one of Sir John's post about a method they use to fill up worn shafts when the bearings ate them, can't remember the details but maybe someone else does.

05-13-2011, 04:02 PM
Braze or mig or tig will stand up to whatever you decide. There is a high temp metalic filler that they use under powder coat, but depending on the color it can show through. Shiny black shows everything.

05-13-2011, 06:25 PM
If the part is very large, I'd be concerned that TIG or MIG on one side would warp the plate.

05-13-2011, 06:50 PM
If the part is very large, I'd be concerned that TIG or MIG on one side would warp the plate.

Or thin. Good point.

05-13-2011, 07:12 PM
braze it.
..with welding you will be chasing around for ever ..as there is usually a depresion around the weld...which isnt so bad if you are putting filler in ..but not for plating or chroming

all the best.markj

05-14-2011, 01:22 PM
Decorative chrome platers plate pitted or rough surfaces with copper until the copper can be buffed smooth. Then the finish plating has a smooth substrate to adhere to.


brian Rupnow
05-14-2011, 02:46 PM
Once you get a price from a reputable chrome shop, you will probably have it powder coated.:eek: :eek: Most powder coaters will recomend a filler that works with their paint process.

Mad Scientist
05-14-2011, 02:47 PM
Depending on just how smooth a finish you need a powder coatings thick film my be enough to fill in small scratches.

Filling the dings with solder should work if you use an alloy that has a melting point above the 400 degrees needed to cure the powder coat.

05-15-2011, 11:13 AM
Thanks to all who have replied. The solder technique is most to my liking due to low heat input and ease of smoothing after soldering. Anyone have any suggestions at to what solder might be used? Something that has a melting temp a hundred degrees of so above 400F, but is easily workable and adheres well to steel.

05-15-2011, 11:54 AM
The silver/tin solders with about 4 % to 5 % silver will have melting points about 550 to 650 F. Be sure to use a good flux. I like the non-acid paste type since I mostly do gun work and it doesn't eat the blued finish.


05-15-2011, 03:40 PM

For filling the imperfections, they use this product at the last place I work.


You have to put it in the microwave before.

But you have another option: Powdercoat the part, sand it and repowder it.

That the way they always do!:eek: