Been drilling and chasing pits with steel filler for over an hour. Would make my life a lot easier if I knew I could flow a bunch of bronze over a few pieces I’m working on then file to shape before chrome. Any first hand experience out there? Disclaimer: this is definitely a traditional hot rod part... and definitely not a chopper part.
If using an oxyacetylene torch I would flow if in and then dress up with a grinder and then linish to remove imperfections. Make sure you clean the pits thoroughly before filling. We used brass rod when repairing damaged bumpers / overriders, once dressed and flux removed, the bar was sent to the plater who polished it before rechroming it and leaving with no tell tale visible sign(s) of any repair(s)
Thanks for the reply, 28rpu. And to the others — this will be a tig operation so no flux to worry about. No brass, no silver. I’ve been drilling out the pits beforehand but something is amiss. This is all new metal, clean filler, I’ve even changed filler and tungsten a couple of times. Must just be impurities in the steel.
Have you changed gas bottle lately? I've seen bad gas do exactly what you are describing. Sent from my SM-G900V using The H.A.M.B. mobile app
Chromer and polisher for 35+ yrs here . 1.get all the nickel off in a reverse strip laybare bath at plating shop . 2. soda blast all over esp pits . 3. using greaser linishing belts with kero then animal fat , start with 120 gritt then240 ,320 .clean off all grease till spotless .satin finish with 220 gritt greaseless compound .4. heavily copper plate, 4hrs aprox. .NOW is when pits get soft soldered .I use a small hand held butane blow torch from the smoke shop. file and hand sand to 320 satin finish . 5. recopper ,nickel and chrome . thats why that tail fin trim can easily be 300 dollars each ! But mostly not.
I have done it and it works fine. Biggest job I did was for a really rust pitted set of '40 Willys windshield moldings. Brazed and sanded/polished the spots then asked the chrome shop to plate with LOTS of extra copper as a 'sandable primer'. Came out absolutely perfect.
Make sure there isn't a breeze in the shop, that can easily disrupt the Argon coverage and cause problems. Also, if you're flowing Silicon Bronze over steel to fill pits, you don't need as much heat by far. Make sure you're not re-flowing the steel. Bad gas (or contaminated lines) are a possibility, but unless it's constant in every weld I would suspect poor Argon coverage first. You could also switch to a gas lens on your torch, or if you're already using one then add a Furrick cup that fits over it like the #12 or BBW which have an additional mesh to help direct Argon (and can use higher flow). As Unkl Ian says, silver solder is a possibility too (and there are good low-temp 500 degree silver solders) but I would worry about it getting pulled out of the pits during buffing since it's softer. Otherwise, should work just fine.
I do my brazing the old-fashioned way with oxy/acetylene. Silver solder is nearly as hard as brazing, much harder than tin/lead solder, no problem with it popping out. But why go to that trouble when simple brazing will do the trick?
Ha! Body solder...in a small aluminum colored can. Used it to fill small imperfections when chopping the top on my '36 three window. Older guys said it couldn't be done...it'd fall out, etc. But in thin passes, it worked like lead...filed like lead...sanded like lead. (its silver color made it LOOK like lead!) So...the 'body lead' was really body solder. Never thought of chroming it, though...