Stubborn Bumper Bolts

A

AYooperA

Senior Member
Trying to remove bolts for plating. Heat and oil and tapping have not loosened up so far. Any ideas welcome. Was trying to save bolts but not looking good now.
 

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You'll end up sawing off the bolt end with the nut. Otherwise, the bolt will simply turn inside the bumper bar ends as you try to loosen the nut. Plan on buying a new end bolt and nut, maybe two if you are separating both sides of the bumper bars.
Marshall
 
By the way, the carriage bolt head should be gloss black, not cadmium plated, sprayed silver, bare metal or chrome plated, as we see all the time. With a new bolt, this would be the perfect time to make this area authentic. Be sure to scuff up the head with sandpaper to give the black paint "tooth" that will help keep the paint from peeling.
Marshall
 
New carriage bolts that you buy at the home store will likely have letters stamped on the head to identify them to the cashier who would not know a carriage bolt from a thermos bottle. Either grind off those ID marks or get the bolts from a Model A supplier. As Marshall says, the heads are painted black. Paint does not stick well to plating, so either wire brush or acid etch off the plating before painting. Spacers are painted black, also. I believe the nuts are cad plated?

Looks to me that you may have at least one of the nuts off already and are trying to separate the bumper slats? If so, and whacking the bolt with a hammer and punch doesn’t work, you may need to cut the spacer and bolt mid-span and press the two halves individually. With lots of penetrating oil.
 
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A standard hardware store carriage head bolt may not work. The ones offered by the Model A parts vendors have a "v" nub underneath the bolt head that fits into the corner where the bumper bar ends wrap around. That nub keeps the bolt from spinning while the nut tightened. I suppose one could make a standard hardware store carriage head bolt work, but it might be difficult to keep the bolt from turning.
JayJay is correct - the spacer is also gloss black and the nut is cadmium plated.
Marshall
 
Marshall V. Daut said:
A standard hardware store carriage head bolt may not work. The ones offered by the Model A parts vendors have a "v" nub underneath the bolt head that fits into the corner where the bumper bar ends wrap around. That nub keeps the bolt from spinning while the nut tightened. I suppose one could make a standard hardware store carriage head bolt work, but it might be difficult to keep the bolt from turning.
JayJay is correct - the spacer is also gloss black and the nut is cadmium plated.
Marshall
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Thanks, Marshall. I’d forgotten about that little tang on the underside. I suspect that you’ve assembled bumpers more recently than I have.
 
I had the same problem. It wasn't that the nut wouldn't come off or that the bolt was spinning in the bumper. My problem was that the bolts had rust-welded to the bumpers and no amount of heat, penetrant or pounding would get them out. I ended up sawing out the exposed center sections of the bolt (with the sleeve on it) and drilled out the bolts from the bumpers.
 
Introduce your spinning carriage bolt to a cut off wheel, cutting a slot in the top to be held with a screwdriver while removing the nut. Finished, fill the slot with JB Weld, sand & paint.
 
Thank You all for your input. After 4 hours I got all 4 carriage bolts out of the front and rear bumper. After 96 years they really fought me. Only one came out intact. The rest as mentioned above had to cut, drill out and then drive them thru. I could have just bought repo bumpers and save the $2,000 extra to have these chromed but wanted to stay with the originals. Now on to the headlight shell disassembly for the nickel plating.
 
And what the heck some pictures
 

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I'm glad I don't live in upper Mi. Here in Ohio a set of bumpers goes for about $700. That is quality chrome not flash bang peal off in two years material.
 
Here in Northern California the front is about $700, rears are about $250 each side, so $1200 or so for the set.
 
Time is money. I saved 5 bucks by working on the old bolts for 6 hours. Just doesn't make sense. It's kinda like the people sitting in the Costco gas line for 45 minutes to save 20 cents a gallon - usually about 3 bucks.
 
Your fire wrench is not big enough. Oxygen/Acetylene fire wrench is sometimes needed. Heat to dull red and douse with penetrating oil as it cools. As long as you are re-plating you don’t have to worry about the finish.
 
You Guys are quoting some nice plating numbers. I am going with them as I know their work and reputation. They have already done my radiator shell, dash & related parts, gearshift, spark/gas rods. Very pleased with the quality. They do points cars but I just want it done well and I know paying a premium.
 
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