how do I fix drilled holes in sheet metal

[JackC 616]

There are lots of how to's on the internet including videos. Just ask Mr. Google.

 

Google something like: "filling a small hole in sheet metal"

 

These are from Eastwood:

 

 

http://www.eastwood.com/blog/project-pilehouse/how-to-shave-unused-holes/

[Ed Kennell 36,148]

 I've never been happy with bondo filled holes in sheet metal, looks terrible from the back and unless you dish the repair area, it won't be an invisible repair from the good side.

    Totally agree,  Also if you don't dish the hole so there is a good overlay of the bondo on the metal, it is very likely the bondo plug will probably  fall out due to the big difference in the temp coefficient of expansion.

[refracman 166]

Kelly is spot on. Bondo and lead are toppings not fillers. 

I use either brass or copper as the backer when welding in holes.

the trick that works for me is to use the backer on the finish side and weld it in from the back.

[stevasaurus 22,282]

I'd go with what Kelly said also.  If you have ever seen his work...it is top shelf.  My problem is...there is never a good body guy around when I need one, and I just love working with lead.  I was a cable splicer with the phone company and I have done a ton of lead sleeves for splice cases.  That and using lead in the body shop is getting to be a lost art....but it is still a ton of fun. 

[Bert 760]

 

I use either brass or copper as the backer when welding in holes.

the trick that works for me is to use the backer on the finish side and weld it in from the back.

Good point

 

I'd go with what Kelly said also.  If you have ever seen his work...it is top shelf.  My problem is...there is never a good body guy around when I need one, and I just love working with lead.  I was a cable splicer with the phone company and I have done a ton of lead sleeves for splice cases.  That and using lead in the body shop is getting to be a lost art....but it is still a ton of fun. 

I was going to use jb weld to fill rust pits but now I think I'll try lead just to see if I can learn a new skill.

[stevasaurus 22,282]

Bert...like was said...working with lead is really cool, and I love it, but I think if you really want to experiment with it...try it on something you can throw away.  The neat thing about lead...with a regular propane torch, just get the lead shiny...then you can just wipe it with a good cloth and some styrene (wax) on it.  It files easy, and you can still use bondo or spot putty to make things right.  Like was said, if you use too much heat, your sheet metal will warp and you will play hell to get it back right. 

[squonk 39,193]

working with lead is really cool, and I love it, 

Well that explains a lot right there!                 

[Kelly 1,028]

Don't forget IF you use lead there are special prep things needed before painting and primers not RATTLE can stuff, if not done your paint job will show it, to buy the tools and supplies to do a CORRECT lead job will cost you more than you think, blast the pits and use a good grade of Auto body filler/Bondo, were not working with bondo from the 70's the stuff now days is easy and good stuff, you can buy a gallon that will last most of you a life time, not that it will be good that long, for under $40 try to buy it from a shop that sells paint supplies, they will have better grades of filler, NOT walmart or Auto Zone 

[953 nut 52,317]

 As Martin and Kelly said, sheet steel needs to be repaired with sheet steel, if you use anything else the finished product will not perform well. When an improperly repaired piece of sheet metal is painted it will look great; then you will take it out into the sunshine and the repair will react differently than the rest of the piece and stick out like a sore thumb! Different thickness of the same metal, or dissimilar materials will expand and contract at different rates and show through the paint. Back up the small hole with copper, weld it and file it to the same thickness as the rest of the metal. If you grind it be sure to not overheat it or it WILL warp. Larger holes can be welded up using a patch the same size as the hole and welded using the copper backer. You will want to stitch weld larger patches, weld a spot move around to the other side and weld a spot, go half way between and weld a spot, etc. Stitching will spread the heat around and reduce warping.

 

If you do it right the first time you won't be disappointed.

 

Good luck and keep us posted.

[Road-Track 39]

If it warps from too much heat, you have to shrink the metal to un-warp it.

 

Use a planishing hammer with a wooden block for a backer. This will shrink the metal.

[rmaynard 14,966]

Maybe you just need to find another hood without holes.

[Ed Kennell 36,148]

 

 

Use a planishing hammer

Got a pic of this hammer ?

[pfrederi 17,199]

Got a pic of this hammer ?

[Ed Kennell 36,148]

I have never used one of these hammers, but I am having trouble understanding how any hammering of metal will cause it to shrink. Logic tells me hammering the metal would make it thinner and therefore increase the surface area instead of shrinking it.
I am not questioning if it works, I just need help to understand how it works.  

[AMC RULES 36,961]

[AMC RULES 36,961]

[Ed Kennell 36,148]

Thanks Craig.  The shrinking disc was all new to me and very interesting.   Takes a real artist to do that kind of repair without resorting to Bondo or lead.

[AMC RULES 36,961]

Patience and determination will go a long way too. 

[Ed Kennell 36,148]

I hear you Craig. I'm afraid when the Man was handing out patience, I thought He meant patients. and I said no thanks. 

[Road-Track 39]

The best way is to use a shrinking hammer and a hardwood dolly. You will not harden the metal.  In England the the masters use a wooden stump to shape and shrink metal. If it is good enough for Rolls Royce it's good enough for Wheelhorse.

 

Edited March 8, 2015 by Road-Track

[Bert 760]

This thread has has really generated a lot of good info.   

[Ed Kennell 36,148]

                                                                                             

  I agree Bert.  I know I have learned a lot from following this thread.   I have seen boilermakers do some amazing compound shaping of heavy turbine blades  (2-6"thick steel) using torches and compressed air for rapid heat/cooling of the metal.   But I was not aware the same stretching and shrinking of light gage metal could be done with the planishing  hammers and  shrinking discs.

[truckin88 104]

U can always look for sheet metal here or ebay too...