Do pipes need chrome removed to weld on?

lakeracer69 · #1 (**permalink**) 04-11-2009, 12:10 PM

I have to fabricate my exhaust pipes because no one makes what I want. I have a brand new set of cheap chromed shotguns that I am fabricating with, along with some mandrel bent "U" bends. My question is does the chrome have to come off the pipes before I can TIG weld them to my other pieces? I want to get them rechromed after they are completed.

Thanks

King of Fools · #2 (**permalink**) 04-11-2009, 05:47 PM

They dont need chrome removed but it would be best especially if you are having them re chromed. The areas you weld the chrome will probaly flake causing differences in the thickness where you welded compared to where you didnt. You may not get the proper look.

Milenko · #3 (**permalink**) 04-11-2009, 07:27 PM

For best penetration on your welds, you should take off the chrome with a die grinder or sanding wheel in the area that you are going to weld.

The chrome shop will strip everything else off when you take them in for rechroming.

donald branscom · #4 (**permalink**) 04-12-2009, 01:31 PM

Chrome will not degrade a weld.

BigMikeSimpson · #5 (**permalink**) 04-12-2009, 01:44 PM

Thanks for posting this question and thanks for the responses... I had the same question yesterday ... I bought a set of Paughco pipes to modify because they had the shape and bends I wanted and were cheaper than a Biltwell pipe kit... I had to extend both pipes due to the engine offset and the extra width of the 200 rear and I added the fishtails.

lakeracer69 · #6 (**permalink**) 04-12-2009, 06:27 PM

Thanks for the replies everyone.

Big Mike, great minds think alike! My pipes are going to be almost the same as yours. Shotguns with fishtail tips, but with a 2" diameter

MechWerks · #7 (**permalink**) 04-12-2009, 07:01 PM

Chrome will certainly contaminate a weld and significantly increase chances of crack failure. Along with the chrome is the thicker copper under plating and secondary layer of nickel. All of which will mess with your welds. Although pipe welds are not largely structural, they are subject to intense heat cycles and vibration. The mixed weld will have a different expansion rate in a concentrated area that will fail over time if not sooner from the initial weld cooling.

Milenko · #8 (**permalink**) 04-12-2009, 07:35 PM

Quote:

Originally Posted by MechWerks

Chrome will certainly contaminate a weld and significantly increase chances of crack failure. Along with the chrome is the thicker copper under plating and secondary layer of nickel. All of which will mess with your welds. Although pipe welds are not largely structural, they are subject to intense heat cycles and vibration. The mixed weld will have a different expansion rate in a concentrated area that will fail over time if not sooner from the initial weld cooling.

Amen brother! That is really what I was trying to say - it messes with your ability to get good penetration, not to mention sometimes it can stink, and smoke!

lakeracer69 · #9 (**permalink**) 04-13-2009, 07:00 AM

Mechwerks,

I am going to use ER70S-6 for a filler rod, does that sound reasonable and compatible to chrome over?

BigMikeSimpson · #10 (**permalink**) 04-13-2009, 08:40 AM

I guess I will dechrome the areas to be welded... I am going to wrap them so I am not worried about visual or rechroming.

MechWerks · #11 (**permalink**) 04-13-2009, 04:21 PM

ER70S is a pretty standard filler wire for MIG and TIG welding with the -6 having a little higher strength and maybe a better wetting quality and helps with less than perfect weld materials (although metal should be cleaned as much as possible in most cases). -2 is the other common version, slightly lower tensile, quicker freeze. Either chrome fine.