[murrsue]

A friend tried it once and eventually got fine cracks around the old hole position. Is there more to it than cutting the heads off and welding them flush?

[Magnus_Jager]

They had this on Trucks the other day. I think on the copperhead project?? What they did as I remember it.

1. Make sure all surfaces to be welded are all clean of rust and contaminents. This would include an area larger than the washer inside the bumper.

2. Put a bumper bolt through the bumper and place a washer on the bolt inside the bumper. You may have to bend the washer so it sits flush to the inside of the bumper. Tac the washer onto the inside of the bumper.

3. Cut head off bumper bolt leaving square part to fit the hole in the bumper.

4. Place carrige bolt just under flush with the bumper, so you can fill the depression with weld, and tac it in.

5. Weld the bolt to the washer inside the the bumper.

6. Finish welding around the washer inside the bumper.

7. Finish welding the bold to the outside of the bumper, and grind smooth.

8. Repeat.

The washer adds strength around the bolt, so the bolt should not deform the bumper.

Welding the bolt below the bumper surface gives more weld surface so when you smooth it it still has plenty of metal, and more strength.

I have not used this method but it makes sense, and would probably prevent those cracks you mentioned by distributing the force of the bolt, and more weld to hold the bolt.

Hope that helps. If anyone else has some methods chime in, or correct me.

[murrsue]

Thanks Magnus. I could see how that washer would help.

[Neophyte]

My question with regards to welding the bolt to the washer on the inside of the bumper is : How do you then get the bumper bracket to sit nice and flush against the bumper or inthis case against the washer? Do you have to enlarge the hole in the bracket to allow it to slip over the weld?

[Magnus_Jager]

That is a good question, but depending on how big the weld is you may need to open the hole in the mount a little bit, or grind down the welds a little if they are excessive. As I said this is a method I have yet to try. Saw it on TV, but it seemed to cover the concerns of the bolt pulling out, or cracking free by giving more surface area, and multiple weld points to distribute the stress.

I suppose the best source of info on this would be the show Trucks. I just emailed the show on their info email for printed directions or a link to them on the web.

[murrsue]

The weld would be ground smooth. The bumper would be moved out the thickness of the washer and weld but there should be more than adequate adjustment in most bumper brackets to adjust for this.

[MARTINSR]

I think the reason for the washer is only to "set the depth" of the bolt in the bumper for welding thru the hole. The weld holding the washer to the bolt wouldn't have to be much at all. Just a light tack is all it would take. Later the washer could even be removed if you wanted. It is not doing a single thing once the bolt is welded in, you don't even need it.

The trick is to get FULL penatration when welding of the end of the bolt to the bumper. If you cut the head of the bolt off (you don't even need a bumper bolt for that matter) and hold the bolt somehow (this is where the washer helps) so it is just about half the way thru the bumper. If you bevel the edge of the hole, and the bolt is down in the hole half the thickness (about 3/32") and you weld a nice hot weld STARTING ON THE BOLT to ensure good penatration before moving up onto the edge of the hole that bolt is going no where and won't crack.

One thing you want to do is fit the bumper to the brackets so it perfectly mates. If when you tighten the bolts it forces the bracket to twist into shape or the bumper to twist or what ever, THAT can cause you problems if you haven't welded perfect, it can add to failure.

Brian

[troy-curt]

I've always welded them on the outside with no washer. And bolted to the car where they go. Never had one crack yet.

Troy