I had the information for a place that can acid dip bumpers/ brackets ect in Michigan.. I cannot find them or maybe they went out of business..Anyone know a place in Michigan that does this kind of work??...thanks in advance..

I'll get his info tomorrow for you, He did excellent work on a few large and small pieces including delicate interior trims and braces.

How much weight can you expect to lose on a typical bumper that has been dip?

Realistically, I believe that any more than half the weight off the items in question become almost unusable.
I had to instruct the dipper on how much percentage could/should be taken off even though he had a good idea of how much could be safely taken off. I gave him interior trim off my car, radiator support for my friends Stingray and various brackets. Some were half off their weight and others were only a quarter off to make up for strength.
It's a detail and time consuming process to do it properly with out it coming out of the vat looking like a skeleton.
Be careful what you ask for, but it is indeed super trick and lots more guys in classes are using the method more than you think.
In the case of the Bumper, I went with a custom built thin 321 stainless that came out at 7 lbs or so from its 21 lbs or so IIRC

lots of work but light in the long term of things.

Thaxs.............. Oz's equal pounds. If I knew of a dipper here locally I probably will try it.

The big dipper is in Detroit.
If needed, E-mail me and I'll get you in touch.
absolutleestudio@yahoo.com