Newbie - Plugging holes?

I have a neighbor who has a piece of angle iron about 3/8" or 1/2" think that he plans to bold under the front of an old, but sporty, auto he is attempting to restore. Most of one side of the angle iron has been cut off so it's about 4' x 1' angle.

This is to bolt a tow bar to and to protect the lower front of the vehicle from curbs, etc.

THE QUESTION: This has several holes (? 1/2") that need to be patched and I was wondering which is the better way to do it. I considered just making a bead around each hole, letting it cool, and making another bead till the hole was filled. The other option, I thought, was to place a bolt in each hole and weld the bolt in place from both sides. In either case it would then be ground smooth for painting.

Actually, I considered trying one both ways and seeing which seemed to work best for me; but then - I thought I'd be real smart and ask those who know! :-) Perhaps some of you will prefer each way, or a different way but I'd like to know your preferences and possibly why it seems best to you. He's in no rush, but we may do this this afternoon if things work out right for both of us.

Thanks in advance,

Al

Reply to
Al Patrick
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I've had pretty good luck by placing a piece of sheet copper down underneath the hole before I start the weld. I'll start on the bottom and work my way up in a slight spiral pattern. This seems to work pretty well. You can get copper at your local home mega mart in the roofing section. It doesn't take much.

My .02 Thanks, James Walsh Jr.

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Reply to
James Walsh Jr.

One option is to leave the holes in place. It may look bad but if the holes are in the center of the long side, they probably aren't going to make much difference. If they are right next to an edge, they will likely need to be plugged.

If you just want it cosmetic, stick a suitable short piece of rod in, weld in a circle and grind it flush. The weld will not pentrate to the full depth so this is not a particularly strong option.

You can also stick a small piece of rod in the hole to give yourself something to weld into. Think about a piece of 3/8" rod about 1/4" long centered in the 1/2" hole. Weld on both sides and grind flush.

The pros would just weld it solid using either rod or wire. It helps to put a copper backer block on the far side. Any thick piece of copper will do, 1/2" x3" square would be ideal. It sucks up the heat on the far side, keeps you from burning through. Work from one side, then do a quick clean up weld pass on the far side.

All this presumes that you have a welder suitable for deal> I have a neighbor who has a piece of angle iron about 3/8" or 1/2" think

Reply to
RoyJ

Thanks Roy & James. I'd not have thought about the use of the copper, especially as a "heat sink" to soak up the excess heat. I was thinking about something just to prevent the molten metal from dropping through the hole but didn't know exactly what.

I forgot to mention with the initial post that I do have a tombstone type welder, but it is AC/DC and I have an assortment of rods. The machine is marked DC CC and AC CA. I was thinking DC electrode negative (?) would deposit more of the rod onto the surface to plug the hole faster. (Don't have my welding manual handy right this minute. I'd need to confirm that and also the appropriate rod.)

It's mainly cosmetic. He wants it to protect the underside of the fiberglass body from curbs, etc. and also to provide a point of attachment for the tow bar. It needn't pass close inspection, but being down low any extra holes might be a place for mud, etc. to collect. The work won't need to be stress tested. :-) Someone else has already welded his bumper of 1 1/2" or 2" tubing - also to protect the front end.

Oh, it's a VW chassis with one of the little classy bodies with gullwing doors. If he ever gets it all finished it'll look real nice. He's fixed a bit of body work on the fiberglass and is almost ready for the primer coat of paint.

Due to his schedule and something else I have to do this evening, and tomorrow, it'll probably be Wednesday before we get to it.

Thanks again,

Al

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RoyJ wrote:

Reply to
Al Patrick

That is what I have done, only rather than bother with the copper, I just tacked a piece of sheet metal to the back side. It was enough to help hold the puddle and I could continue to add to the weld.

Reply to
Rusted

pretty well.

considered just

another bead

seemed to

Reply to
MachineShop

Reply to
RoyJ

Well, I got this little job done today. Since I had an AC/DC tombstone welder (Craftsman - ? made in Italy) I decided to go with DCEN. I didn't have my welding manual handy and just decided to see what happened working from the best memory I had. I think I'm correct in that the electrons flow from the negative to the positive terminal and since I wanted to deposit the rod into the holes I thought DCEN would be the best. I used 3/32" 6011 rods and about 60 amps. For the last pass I cranked it up about 5 amps to try to smooth things out. :-) I'm sure I didn't do enough chipping especially at first and it sure wouldn't pass an x-ray exam. None of it was critical anyway. It was all cosmetic.

Since I didn't have any copper handy and had plenty of boards I placed a board under the side of the angle iron so it was flush with the work. Also, I did the back side first so I'd have something to build from to fill the hole to the front.

Everything seemed to go pretty well. He took the work back across the street and ground it smooth. It still had a tiny bit of pitting but he was tickled pink so we'll probably leave it at that. He mentioned using bondo (?) to smooth everything out, on several parts of the car, before going for the primer coat of paint. He's very happy. Oh, It's a Bradley GT body on a VW chassis.

Thanks for all the help. Oh, this was not my very first "project" as I'd had a guy make me a flatbed trailer. He had installed about 8 embedded tie downs in the bed, but occasionally there's a need to tie across the entire trailer and not use those in the bed. I added 8 more on the outside where he had 4" channel turned out down the sides. I just set them in the channel, welded them in and burned off the little excess length with the rod.

Also, I started an oxy/acetylene cart and after getting the 10" x 20" base framed I decided I need to make a welding table first - so I can clamp everything solid. The frame drew up on one corner so it "rocks" a bit. It's square but not exactly flat! :-)

Again, thanks for all the help.

Al

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Rusted wrote:

Reply to
Al Patrick

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