My First Weld!

[ChickenLips]

Patch panels don’t have to be a straight butt weld.
Sometimes that’s the only option but look into a seam tool like this

https://www.summitracing.com/parts/mal-pf1ev

For long straight patches it helps keep the metal straight and eliminates the chance of burning threw.

Keep practicing but mix it up. Do some butts and some overlaps. Even some T welds the different angles will help you figure out tip positions and how they can change the weld

Once you get better. Then start practicing vertical and upside down. It’s never the same on the car as it is on the bench.

Check the backs of your panels to make sure you have the penetration.


When you finally get to welding patches the two most important things are temp control and corners
Jump around with your spot welds to stop any one part from getting hot and never cut a patch with a corner, give your patches a radius instead of corners. Corners will give you a high spot and then Week spot if you grind them down too far.

Any questions just ask. But mostly have fun it’s a great skill to learn.

[5.4MarkVIII]

when lap-welding you will leave a very vulnerable area for rust to start and spread-that’s why butt-welding is the preferred method.

That’s what seam sealer and rust prevention is for.

Depends on the application but Lap welds are used all the time. At least they were when I was in the game.

[Ponyryd]

That’s what seam sealer and rust prevention is for.

Depends on the application but Lap welds are used all the time. At least they were when I was in the game.

I’m not looking to argue here, just giving pointers. Lap welds are used because they’re quicker and easier to do-not because they’re the right way. I agree you can try to seam seal the backside of some lap welds, but for many applications you cannot access the inside, and spraying rust prevention will of course slow the spread, but the lap will still be a very vulnerable area. In the south it’s not much of a worry, but in our area you and I both know that salt can and will get into areas that are vulnerable, one way or another.
Of course there are times when a lap weld is the only way, but for something of my own, that I intend to keep, I’d be doing a butt-weld whenever possible.

[5.4MarkVIII]

no argument.

talk to ten different guys you'll get 20 different opinions lol, everyone has their own way.

[ZR]

Also sometimes forced into lap weld when working with a panel can't be welded properly due to poor condition or poor quality. In those instances night n day stronger to give if a shot of weld through panel and overlap as needed. Dealing with rust pushes you to pick your battles.

[Uncle Buck]

Current panel mics at 19 gauge. Best to go with 18 or 20 for the patch?

[5.4MarkVIII]

Either or will be fine. If you have one on hand I wouldn’t run out to buy the other

Edit. If your doing floor pans personally I like to go thicker for quarter or fender panels either or would be fine

[Laffs]

Would go 18 personally if I had to buy because once you flatten the welds down you'll likely end up with 19 finished thickness on the repair, but honestly like MarkVIII said if you had one on hand wouldn't hesitate to use what you had first.

[hammerhead]

a flapper disc will give a better result as opposed to a grinding disc... they come in different grades and easier to control how much metal is removed. 18 and 20 gage is pretty thin and you mind find better results with 16 —nicely done it can be very satisfying.