This is my current passion project - I would really appreciate some tips/tricks on welding up rust!
Posted by Remote-Department-68@reddit | projectcar | View on Reddit | 33 comments
Hello! This is my 1982 VW Scirocco. As you can see, it has a lot of rust… Amazingly, the floors and the structural areas underneath are mint as it was dripped on from above (it was in a barn). A lot of the exterior is rough, but patchable with a bit of patience. The main areas of concern - and the reason I’m making this post - are the A-pillars and the ends of the sills on both sides (where they meet the wheel arches). I would really appreciate some tips/tricks for welding structural areas such as these to make sure they’ll be strong and safe for when the car’s back on the road. I’m very new to welding and it’ll be my first time using a mig welder (I’ve had a little experience with flux core before). I know it’s probably not a great idea to throw myself in the deep end like this but I like a challenge! Thanks in advance!
Marsh68389@reddit
Hey mate.
Just start. Yeah listen to all the comments about the specifics but just crack on. You will have to cut a piece out and start again. It’s painful but it gets there.
Invest in a good welder. Either mig or tig. I got on quite well with mig with gas.
You will accumulate tools and experience in the doing.
Scorpius202@reddit
Just a heads-up before you get too deep into the heavy stuff: you really should weld in some temporary reinforcement beams across the body.Since you plan to repair the structural areas the chassis, that metal is going to want to move. Between the heat from the welder and the temporary loss of rigidity while parts are cut out, the whole frame can twist or sag faster than you’d think.Weld in some box tubing across the door openings and maybe an X-brace in the middle. It’s a bit of extra work now, but it’ll save you from having twisted body later. Good luck with the build!
Remote-Department-68@reddit (OP)
Yeah, I’ve seen photos of others putting in support braces when doing pillars and sills. Is it necessary when only doing the sill skins and the top and bottom sections of the A-pillar? Is there a specific way to weld them on so they’re easy to remove later? Thanks for the comment!
lunaticmagnet@reddit
Hard to tell, but most that just looks like surface rust, not rot that needs to be cut and replaced?
megasmash@reddit
The optimistic way of looking at it, is by the time you get this Scirocco all patched up, you'll be really good at welding.
Yeoshua82@reddit
There was this episode of wheeler dealers where I think they had an old Sonnet that really bad rust and they went into great detail on how to properly fix it. I would find that episode and watch it over and over again. Then take it to a shop.
ONE1-ZERO@reddit
I’m a VW guy. You need to clean the surface rust up. You’ll need an air compressor and a media blaster. Then hit the spots with heavy build self etching primer. Worry about patch panels later.
tollboi@reddit
Honestly, buy a cheap gasless flux welder and have a go. That's how I did it.
Only real thing to remember, you need to do repeated racks, not a full pull/push of the weld as this metal is so thin itl just blow holes if you try.
subwoofah@reddit
Id reccomend investing a little more and get a proper welder it is wayy easier to weld with imo
Remote-Department-68@reddit (OP)
I have a small mig welder with a gas bottle which should be way better than flux core. I used to use flux core but it wasn’t ideal and the welder broke too… hence the upgrade.
Tibi1411@reddit
Yeah if you can avoid flux core then just buy a regular Co, its way better for this thin sheet metal.
Also get some thick aluminium sheet as a backing while welding(if you can get to the back) steel doesn't stick to alu and it makes it harder to burn thru
JamesFuckinLahey@reddit
How do you plan to A) ensure all the rust in the frame rails between all the overlapping sheets of metal has been removed/replaced and B) once that’s been done, coat the surface so it doesn’t rust again?
Remote-Department-68@reddit (OP)
For part B my plan is to use zinc weld primer on the back of the metal I’m welding in as well as treating surface rust behind the panel (e.g. inside sills) when necessary with this Granville rust killer stuff I have. Once it’s all welded up I’m gonna fill everything with waxoyl with one of those probe things.
Part A is where I’m struggling a bit with a plan. I’m basically gonna cut out rusted areas then see what it’s like behind (e.g. inside A-pillars and sills). If I have to cut out another layer my plan is to try and replicate it recreate factory seams. I may also need to brace the doors but I’m not entirely sure what with. You don’t need to brace with just the sill skins, right? And would I need to brace for doing the tops and bottoms of the A-pillars?
McGee4531@reddit
You don't believe up rust. You cut it out if you're welding there. If your not welding, you can either grind it to clean metal, treat it with an acid, or put some rust reformer on it.
subwoofah@reddit
Damn and i thought my projects are rough!
Vast_Builder1670@reddit
Are you going to be able to find the windows, if you don't have them all intact?
Remote-Department-68@reddit (OP)
I have all the glass, I’ve just removed everything so I can weld it.
Pyropete125@reddit
Hi, Im new to surgery but I plan on operating first time on a brain. Here is some pictures of how much surgery it needs.
Does this sound ridiculous? Welding is a skill that takes years of practice to do it properly.
Get practiced with non critical stuff or send it out to do properly. You will warp the crap out of those rusty panels - even if you know what you are doing. I'd recommend cutting those from a good shell. Any money you save will be spent doing the extra bodywork.
The cost of body panel work is the same for a Vw or a Porsche or whatever. But you need to know what the value is when your done. 30k into a 10k car isnt that smart of a plan.
Good luck.
Reizei_Mako_@reddit
Find some Ospho if it’s available in your area. it’s a rust converter that I like to use in areas I can’t physically remove surface rust from or to wipe over any areas ive already done any rust removal to help catch any real small spots that might get missed. Let it dry and throw some paint over it and it’ll give you a lot more life out of your original metal.
JCDU@reddit
Urchfab has great no-nonsense videos on this stuff:
https://www.youtube.com/watch?v=v9yjCc-yNEQ
u/narcoleptictoast is right, you don't weld rust - you grab the wire wheel in the grinder and keep going until you have clean shiny metal everywhere that you can then join the new bits to.
Confident-Benefit600@reddit
Walk away
sgt_Berbatov@reddit
Should read: "This is my rust. As you can see, it has some 1982 VW Scirocco under it."
Remote-Department-68@reddit (OP)
To be fair, absolutely true lol.
sgt_Berbatov@reddit
Seriously though good luck with it. Don't throw too much money at it until you know the body is sorted welding wise. Don't be afraid to take a long time at the welding, it's better to get it right than to rush it.
Remote-Department-68@reddit (OP)
I’m hoping to have the welding done by September which will hopefully be enough time.
phalangepatella@reddit
Do you have a special attachment to this car? This is rough for a first time resto.
Unless it’s purely for practice and the final outcome isn’t critical.
Otherwise, finding an easier project to start with is a good idea unless you’re in it for the challenge alone.
Remote-Department-68@reddit (OP)
The final outcome doesn’t need to be perfect, just solid. This is one of only two remaining mk2 Sciroccos left where I live so I feel it ought to be saved. Finding another project isn’t an option.
narcoleptictoast@reddit
This is how you weld rust - you don't.
You need to cut the metal back until there is NO rust. Welding through rust is pretty annoying, and generally the rusted metal is extremely thin. It's really not even worth fighting with it. Once you have the holes cut back to good, strong, thick metal you can make your patch panels. I like to use file folders for the templates. Might be worth investing in some simple panel shaping tools (a decent vise at a minimum) as they will make it much easier to shape the panels.
Don't worry about making the unseen panels look perfect. Spend the time on the exterior panels that you can actually see. Try to use bondo only as a small skim coat on top of the panels.
Remote-Department-68@reddit (OP)
This is great advice! My workbench only has a wooden vise. Would that do or do you think I need a metal one? Yeah, I’m not too bothered how pretty the repairs look, I just want it to be strong again.
That bit next to the fuel filler cap on the rear drivers side has me a bit divided. It’s still solid enough that when I poke it with a screwdriver it doesn’t dent or go through, but it’s clearly much more flexible than the other side (i.e. the metal is thinner). The problem is there are holes on the corner next to the rear light and to patch that I’d need to weld the that area. I don’t really want to cut out that massive section and try to replicate it so I’m not really sure what to do.
Frundle@reddit
In some places you should be able to make replacement and patch panels from normal sheet metal and weld them in. Its a valuable skill to learn.
For other parts, you're going to need good replacement sections cut out of a donor car. That driver's side A pillar for example.
LandCruiser76@reddit
Pray. I’m doing one right now. And all I can say is pray. From the photos it looks like a lot of the rust is on the firewall and technical places- this car will be a money pit if you want to do it all “right” but if you’re ok with bondo you could probably get it done.
My biggest tip is to keep the metal cool- don’t lay down long welds. Small little welds equally spaced and rotate through them.
Remote-Department-68@reddit (OP)
Not really bothered if I have to use a bit of filler, I just want it to be strong and not made of air…
I’ve watched a few YouTube videos on welding sheet metal and all of them have saying about distributing heat and keeping panels cool to prevent warping so I’ll definitely be using that tip, thanks.
LandCruiser76@reddit
Yeah. My previous owner did chicken wire+ Bondo and that car looked flawless, until the surfacing wheel hit it.
What kind of time can you reasonably put at this car- if I had to guess you're easily looking at 1,000hrs of work for a novice. (including paint and assembly)
You might be happier starting with something with less organic weight reduction.