I'm putting the cargo floor back in. I've drilled the holes using a step drill bit to about 5 or 6mm I think. Cargo floor sits fine for an NOS panel. When I weld through the holes in the cargo floor all I'm getting is the welds popping

I cannot seem to get the welds to hold. I've tried increasing the current, dropping it, wire speed up and down etc but it keeps happening. The welds are literally not penetrating at all. It's almost like the welds just sits in the hole and on top of the top hat for example and isn't holding to the metal underneath.

I'm kneeling along the drill hole lines and using my body weight to push the panel down tight to the support section. I've then been welding into the holes in a line. Is this right?

Should I be welding for example on one end and then switch to the opposite end (same line though) so the heat doesn't build up?

What is causing the welds to simply keep popping? Is it the heat? Maybe the holes are too small?

HELP

To me it sounds like the steel of the top hats is contaminated with something as you usually only get poor penetration with naff steel? Did you use any primer or anything on the steel underneath? My advice would be to take it off and check the steel is super clean and then give it another go.

As above make sure all metal is clean and free from grease solvents etc

Bugger. I thought it would be okay but I reckon that's it. I guess I'm faced with the problem now of some of the welds have held but luckily the majority have not. Good job I stopped and walked away from it.

I guess a good idea would be to drill back through the welds I have done to mark the area that needs cleaning and then maybe use a permanent marker to the holes I haven't welded to again mark the area that needs cleaning?

Don't want to needlessly clean the entire top hat or I beam I suppose.

Either way the floor is coming out again

Photos on my 67 velvet green post!

Yes bud tthat's what I did when I put the cargo floor in the 51 marked the holes with a black marker so I only cleaned up the bits that needed welding bud

Thanks mate - luckily I'm only talking about 15 or so welds on the whole floor otherwise it could have been a lot more painful. Thanks again.

Crooky wrote:Thanks mate - luckily I'm only talking about 15 or so welds on the whole floor otherwise it could have been a lot more painful. Thanks again.

You have made great progress so far, its only a little headache keep up the good work

thanks mate - appreciate that.

Are you using gas with your mig or gasless wire?

If your gas pressure is to low you will get bad penetration as its not providing a shield, try welding new steel together with the settings you have if its ok then probably contaminated steel but if problem persists then it's your welding/welder.

cheers oily - reckon its contamination as I the beams were fully primered up. Doh! Live n learn.

Using gas with a MIG.

I've welded new steel on the rest without issue.

Replied on your build thread.

Try using weld thru primer
worked a treat on mine
turn the amps up ,try to weld the top hat first dragging the weld pool to the edge of the panel

Back of the net

Drilled out the welds which cleaned the beams at the same time. Welded direct to the beam and then joined the weld pool to the cargo floor. Once I got the hang of it I was motoring through....................then I ran out of gas

Still I got one half done and primed. Cheers guys.

just to confirm weld through primer is not really weld through, if your plug welding spray both in weld through primer then scratch the paint away through the hole you drilled and yoi will have success,