Welding up drilled holes in floors.
 

Its hard. What is the trick? Seems like I weld, grind, weld, grind, etc and still have tiny "missed" spots where light comes through. I want it to look like the hole was never there-Help!

A piece of copper held tight to the hole should help. The weld will not stick to copper but will still carry the arc. When you get to the edge of the hole watch your heat. You will want to get on and of the trigger more. Do your finish grind.

What about a little jb weld applied then sanded off in the area?

That's cheating.;)

If these are like round holes tack them shut and them do a continous arc in a circle. Or if possible do the continous arc in a circle.

If these holes are that small you can JB weld them. You should be able to weld them up.

I taped a penny on the back and did one. Worked pretty good, 15 to go. For some reason there were 16 holes drilled in the trunk alone. Jeez.

I used the penny trick also, works pretty good.

How about screwing in a bolt into the hole, tacking it in around it and grinding down the bolt smooth afterwards? Any problems with that?

I had a lot of trouble with this when I started welding. Tried the penny thing and all sorts of stuff. It justs takes practice. I can now weld in holes very easy with nothing behind them. Play with your wleder settings. Start on an edge, and pull it across the hole. Or larger holes, go around in a circle building the edge and then you have it filled.

If you are getting them filled but have pin holes, I'm guessing you need to turn up the power on the welder a little and play with your feed rate. Use thin wire. Or you need to clean things up with a wire wheel. I'm assuming your using a MIG.

Yes, C25 gas, .024 wire. Heat on low setting. Thanks everyone so far.

A trick I use MIGing holes: I grab a scrap of sheetmetal, a cut-off a few inches long. Then with aviation snips i cut a piece to fit the hole. Don't cut it all the way off, cut it ALMOST off. (sometimes I use wire cutters to do the last cut on 18ga - seems aviation snips like to cut the piece all the way off no matter how careful I am). I leave it hanging off the scrap handle. Then I bend the hanging piece so its easy to hold in the hole. Zap it a couple times. Then wiggle the scrap back and forth to break the handle off. This leaves the little piece tacked in the hole. Easy to finish weld from there.

When I'm welding floor pans, especially small welds, I make double sure I have my grounding clamp as close as possible and on bare metal. it makes the job much easier.

Never thought of that...

A trick that I use is i take a bolt and tack it to the piece I'm welding in. Then put the ground onto the bolt and hold onto the ground clamp as I tack it in. Finish the job and break off the bolt. Remember if you do it this way the current is only running between the stinger and the ground. Saw a job on a new wheel loader welder put a ground on the back of the loader did some retrofitting around back counterweight and then moved to the front to work on the quik-attach bucket,.... didn't move the ground. Finishes the job and owner picks up machine,,,,, immediately complains of a binding sound in centre of machine.... Problem was electricity flowed from back of machine at ground to front of machine at stinger (welding rod) in the middle of the machime are bearings that allow the machine to articulate. Electricity arced across bearings and ruined them. Two days later and several thousand dollars out the door machine was once again ready for the owner to pickup. NO profit in that job.

I do this too...also, I will use scrap welding wire for the same purpose. Sometimes I twist it up to get it thicker.
I definitely am not great at filling holes though. In fact, I kinda suck at it.

This is how you do it. General rule of welding is to not use weld to fill holes.

I have to fill a hole that's about 3/8" dia. Good info in this old thread!

Yes good ideas. I burned thru welding sheet metal. Drilled the hole round, then cut a piece of sheet and ground it till it fit the hole. Welded a finishing nail in the center to hold it while I welded it in.

More tips.

http://www.spiuserforum.com/index.ph...ng-holes.3776/

And how old is your wire? Old wire usually has corrosion on it and that will cause porosity problems.

Eastwood sells a sheet metal hole plug kit. Saw their video and they look they work pretty good. Unfortunately the smallest plug is 3/4".

[URL="https://www.eastwood.com/eastwood-sheet-metal-plug-kit.html"URL]