MIG for vintage car restoration?

[the snooper]

the last picture you can see it has been welded before as you have left the old weld there, you need to remove the old weld to do a better job its pointless welding on top of weld

 

[scourtaud]

The last picture is after a quick cut to see what was behind, I need tu cut a lot more to remove the 20 years old repair and do it edge to edge rather than overlapping the new with the old which is what was done.

 

[marlinspike]

To make a more accurate template for a patch, I have found it useful to put a few lines of masking tape over the area, then mark on the tape and cut the rusty bit out. The masking tape comes with it, and gives you the exact size. This is especially useful where there is a curve in a panel - you flatten the tape out, use it as a template, then put the curve into the patch before welding it in.

 

[scourtaud]

To make a more accurate template for a patch, I have found it useful to put a few lines of masking tape over the area, then mark on the tape and cut the rusty bit out. The masking tape comes with it, and gives you the exact size. This is especially useful where there is a curve in a panel - you flatten the tape out, use it as a template, then put the curve into the patch before welding it in.

This is a very good tip, thanks a lot...

I haven't done any more cutting / welding, I'm removing the rest of the trim, stripping the hidden paint behind the dashboard and then I'll separate the body from the chassis and get to work. It'll be easier for many things.

 

[scourtaud]

I thought a quick update was mandated since I'm about to start the true welding now the car has left the chassis. I've also ordered enough metal to build a rotisserie for the body and a simpler one for the chassis.

This is where I'm at right now :

 

[scourtaud]

Hi to all,

I've had a chance to play a little with the MIG in order to build a chassis rotisserie (body comming next).

All the welds are not pretty but it holds strong. I'll be tackling the body rotisserie next, It should keep me busy. Its also a very different type of weld for me since its not thin sheet metal that I might blow through in a second, it needs more time, more power and slower welding. I'll admit I like it.

Between this and all my practice, I've almost blown through my first gas bottle. I'm not sure I have enought to fully weld the body rotisserie so I'll tack it all up and see what I can do until next week when I can get a fresh bottle.

 

[mpats]

A small thing I do when cutting out sections, not done any car work, but I will imagine it will work on car body work, and it may help you. If its square, or of a similar shape (won't work if trying to cut out a circle!), drill a hole at each corner or where the start/end of your cut will be then cut up to the hole with your grinder/disc. This saves cutting past the corner on any given side, and gives you a nice start or finish point for your cut.

Nice project by the way.

 

[scourtaud]

Hi to all,

This is a thank you message to the website in general and the forum members, on April 9 I did my first MIG welding (not good) and today I finished a car rotisserie. Its been a nice learning curve and it really feels great to be able to build something and see it work.

There was a tense moment for the first rotation but it didn't blink an eye and then there was testing with friends sitting on it, adding about 160Kgs on each end (more than triple the weight of the body) and nothing moved once again so I added some braces diagonaly on the outer supports just in case (I'll sleep better) but I now have a better idea of the strenth of the whole thing.

So thank you, I'm not sure I'd have tried my hand at welding without such great tutorials and advice and such a welcoming community. I'll now be moving on to bodywork (a hole other story) but I've got more confidence and I can't wait to get to it... Starting tomorrow.

 

[scourtaud]

So I did my first true repair last week, it did not go without a few troubles, mainly burning through but I got the hang of it towards the end.

This is the front bumper mount.

Before :

Behind the skin :

Cuts to repair bad sections :

Welded with rust converter :

Copper painted (also did the back side of the outer skin piece).

Welding :

Grinded :

Its not perfect, it moved a little bit with the heat so I'll leave it as is and might do it again later on if I feel I can do better.

If you see anything I did wrong, please let me know.

 

[Pete.Forrester]

Hello,

Firstly what I would do If i were you is to actually clean off all the rust in the first place. Don't use angle grinder for it, use a wire brush which is less abrasive to surrounding metal. Any bits that are beyond repair you cut off. But you have to remove all the rust first in order to be able to weld a good piece in otherwise it will start to rust within months again. Sorry for being harsh, but with above repair you did more harm than actual repair, as this particular place was not clean enough in the first place to weld patch in.

Yes, use a rust inhibitor, but at places that have been cleaned off first. Stop using a copper paint and go for high zinc content primer. Copper rusts where zinc protects. So basically a clean off first, then rust inhibitor, wipe it dry after 15-20 min and light coat of zinc primer (only use high content ones like 98% or so). Weld edges do not have to be covered in primer, so you can leave a margin there. But remaining parts of plate should be covered with it.

Start using smaller diameter cutting discs and apply less pressure whilst cutting - this will provide you with better cut surfaces (you do know you have to clean off the face of the cut after cutting it with disc?) and you will not damage the surrounding areas. Same when you remove excess welds, apply light pressure, otherwise you burn the metal and it will start to rust despite best protection treatment applied later.

Start using a cardboard templates instead of trimming a piece of metal so it fits. This will save you a considerable amount of time and metal sheet.

Meal sheet has to be cleaned off from its surface coating. You will be able to weld it MUCH more easily, especially on gauge steel.

Consider tapping all the welds in with a small mallet first before you skim them.

After you finish with the area wipe it off, de-grease, apply zinc oxide primer and zinc primer (allow cure times respectively). You can use a weld seam on the welds to completely seal them in case.

 

[scourtaud]

Hello,

Firstly what I would do If i were you is to actually clean off all the rust in the first place. Don't use angle grinder for it, use a wire brush which is less abrasive to surrounding metal. Any bits that are beyond repair you cut off. But you have to remove all the rust first in order to be able to weld a good piece in otherwise it will start to rust within months again. Sorry for being harsh, but with above repair you did more harm than actual repair, as this particular place was not clean enough in the first place to weld patch in.

Yes, use a rust inhibitor, but at places that have been cleaned off first. Stop using a copper paint and go for high zinc content primer. Copper rusts where zinc protects. So basically a clean off first, then rust inhibitor, wipe it dry after 15-20 min and light coat of zinc primer (only use high content ones like 98% or so). Weld edges do not have to be covered in primer, so you can leave a margin there. But remaining parts of plate should be covered with it.

Start using smaller diameter cutting discs and apply less pressure whilst cutting - this will provide you with better cut surfaces (you do know you have to clean off the face of the cut after cutting it with disc?) and you will not damage the surrounding areas. Same when you remove excess welds, apply light pressure, otherwise you burn the metal and it will start to rust despite best protection treatment applied later.

Start using a cardboard templates instead of trimming a piece of metal so it fits. This will save you a considerable amount of time and metal sheet.

Meal sheet has to be cleaned off from its surface coating. You will be able to weld it MUCH more easily, especially on gauge steel.

Consider tapping all the welds in with a small mallet first before you skim them.

After you finish with the area wipe it off, de-grease, apply zinc oxide primer and zinc primer (allow cure times respectively). You can use a weld seam on the welds to completely seal them in case.

Thank you for this, I'm learning on the way and this piece will get redone towards the end because I'm not fully satisfied with it.

I'm however perplexed with the fact that copper rusts, It is sold as a welding primer. Is it really worse than zinc (I thought the fumes were bad for me)?
All of the car will be covered in epoxy primer when I'm done.

Since this repair, I've bought a pneumatic disc cutter with 76mm discs, it makes cleaner cuts and is much more precise to use. I've also been using cardboard for templates. This was my first repair and it wasn't great.

Why tap the welds with a mallet, what is the desired effet?

Thanks for the advice

Sebastien

 

[Pete.Forrester]

Copper may be good for the bolts to prevent them from seizing, but on bodywork from what I have learned you use zinc. like you said copper primers seams better primer in weld through applications but you want a primer for a body work application that can be painted over at later time to a very fine finish. Copper is as well higher on the galvanic table; explaining that in massive shortcut copper is the metal that will corrode faster than zinc, it's the reason you have cars coming from manufacturers with zinc coating but not copper.

When you will do the outside body work you tap the welds to bring them below the surface before skimming them. It leaves better bonding between panels. Any imperfections can be filled with putty.

I am really surprised that you undertook such a massive task without prior study of body work repair. I would go very slowly if I were you over the car with de-rusting first.

Last thing. If you have the body off the chassis weld in some support inside so you dont distort the body. Body was designed to rest on chassis not really to be turned over and kept is that position. Just weld in supports across the A and B pillars so it does not warp or anything. You would have to do it anyway if you intend to work on the foot wells.

 

[scourtaud]

Understood for copper, I've learned something and will ordre zinc primer for the rest of the car.

I decided to undertake this project because its not a complicated car, most parts can be bought rather than made (even though I'm trying to make some) and I wanted to learn. I've got time, I've got the space where I can work so I decided rather than just throw money at the problem I'd give it a try, I've been doing all the mechanical work ont this car for 10 years (up to building a performance engine from scratch) and I've always wanted to try bodywork.
Its a steep learning curve but I'm currently working on the chassis and making good progress and I'll get back to the body once its done.

Before I even began, I had a deal with a bodyshop I now that if I found myself unable to complete the car, I could bring it to them as is and they'd pick up the work where I left it si I felt good about trying and I knew I had a way out.

My working plan is to do the repairs, apply some now zinc primer where the metal is bare and once all the repair I've seen have been done, the chassis and the body will be sent to sandblasting and what they call metalisation (cold) before recieving an epoxy primer for the body and a chassis coating for the chassis. Once I'm there, I'll try my hand at painting on some spare pannels I've got and depending on the result, I'll either send the body to a paint shop or finish the work myself.

As for the braces, they've been welded before the body left the chassis and I've been checking measurements once a week, nothing's moved. The good thing about the beetle is that the body is quite light, it can easily be lifted by two "normal" adults so efforts on the braces are not that bad.

 

[Pete.Forrester]

Great about the braces.

Sorry, I did not know about your mechanical experience, this is obviously an advantage as you can get your hear around the tasks much better. I remember when I started tinkering with the body work couple years back without any sort of knowledge - I end up scraping the car - then decided to go to college. Should do it other way round really....

Sorting the chassis first seams like a good plan, you do need better eye for the body as that's what ppl look at to judge your skill.

Wright, leaving you to it. Keep doing great work.

 

[Riley]

Really enjoying this thread. This is the reason ive joined the forum as I will be tackling a similar project over the coming winter months and am currently gathering information from threads like this.