Welding panels

[1967 MkIII]

Evening all

This winter I'm going to restore my Spitfire wihich mostly means new outer panels as the existing ones are either rusted through or dented in many areas. I'll get a pro to do serious bits like sills etc but I'm wondering how panels are spot welded together to see whether I can do it myself. I've some experience with arc welding but so far I've only done fairly chunky iron bits for home or garage projects.

Can I use an arc welder on a lower setting or is a different type of welding used?

Any tips appreciated as always!
Thanks
Steve

[Spitfire2500]

Arc welders are generally far too brutal for panel work. Best option for home/DIY is MIG. Lots of info here: http://www.mig-welding.co.uk/

Gas is still an option of course -- but probably not the best for home/DIY these days for safety reasons.


Edited to add - if you're familiar with Arc welding you should be able to get up to speed with MIG welding no problem.

[1967 MkIII]

Thanks for this, really good site!  

I always thought the G in MIG was gas...  :B

[piman]

Hello Steve,

yes you are right, Metal Inert Gas, the gas shields the weld from oxygen. Bill is referring to oxy\acetylene gas welding, which is a very good method of welding car panels. More expensive equipment and probably harder to learn?

Alec

[Glenn]

You can buy electric Spot Welding machines to do this Steve.  Have a google or go to Machine Mart etc.  They make a very neat job and not too hard to use.  Downside is the factory would have had ones with very long arms to reach all the bits of the car they needed to, and the hobby ones might be a bit limited!  Not sure how many folks would own one?

Like the learned gentlemen say, MIG is the way to go.  An alternative to spot welding when joining 2 panels is the MIG "plug" weld.  This is drilling a series of 5mm holes in one panel and welding in the middle of the holes until the hole fills with metal and the 2 panels fuse together.  Looks like a neat blob.  You'll probably pick up how to do this pretty quick - it's not as hard as seam welding which takes a bit of practice on thin body panels, especially ones that are a bit rusty.

[Clive]

If you are serious about doing some of the welding you may as well do it all. Sills are OK to do once you get your head around how they fit together and so on.
I would really recommend avoiding the small SIP machines, and if buying new a small clarke, very good, and really better than the 150A version I got (lowest setting can still be a bit vicious, a 130 or less would have been better, I used a 90A one for about 10 years, brilliant)
I also use gasless mig. Wire more expensive but no gas to buy, so about same running costs or cheaper. But good outside as wind blows the gas away very easily. Not quite as neat as gas mig, but can be very hard to tell. It often looks messy until wire brushed as it gets coated in a brown/white residue from the flux core. (I presume stick welding is similar?)

I would also recommend a hole punch/joddler as it saves all that drilling for the plug welds. Not cheap, but so worthwhile. The joddler can be handy for repair panels too. eg:  

http://www.ebay.co.uk/itm/Standard-Joddler-Joggler-Edge-Stepping-Tool-/260531537874?pt=UK_Hand_Tools_Equipment&hash=item3ca8e3c7d2

[Elma fud]

Personaly l have found the reproduction panels very thin and you have to be very carful when plug welding with the Mig that it doesn't burn through, if you can put the holes in the new panels and weld to original thicker panel then that should be better.
Altenatively you could hire a spot welder as you will get an original look joint, but they are heavy :-/

A hole puch tool is much better than drilling because you don't deform the flange as much and it will not need to be dressed afterwards.
Frost weld through zinc spray is very good and will help to protect joint aswell as giving conductive layer ;)

[1967 MkIII]

Thanks for all the replies, good direction for more research from my side

[1967 MkIII]

cliftyhanger wrote:

I would also recommend a hole punch/joddler as it saves all that drilling for the plug welds. Not cheap, but so worthwhile. The joddler can be handy for repair panels too. eg:  

http://www.ebay.co.uk/itm/Standard-Joddler-Joggler-Edge-Stepping-Tool-/260531537874?pt=UK_Hand_Tools_Equipment&hash=item3ca8e3c7d2

Thanks clifty. JOddler looks the tool for the job, thanks as i'd not heard of it before. Also came across this cheaper version :) though i'll go for the real thing

[JensH]

2057 wrote:

Thanks clifty. JOddler looks the tool for the job, thanks as i'd not heard of it before. Also came across this cheaper version :) though i'll go for the real thing

Go for the real thing - made in Denmark; its a quality product - one of the very few made here  :o

As for panel replacement: Its not the welding - you will learn that part (practice on lots of steel sheets, old doors etc first).
What makes the difference is alignment of all new panels, how sill- floor pans, heelboard, lower a- and b-post etc joints.
How you make sure, doors are not sticking out at the lower rear part. Why you should not alter proportions of new panels before you know why they don't fit.

That's what makes the difference between a quality job, and - what is not! 8)

If you are not prepared for this, you are much better of sending your car to eg. jyclassics or some of the other few who knows their stuff.

[TedTaylor]

Only problem with punches is that they often produce a hole that is too small to make an effective plug 'spot' weld - 3/16 or 4.5mm.  I have found that unless you are very careful the wire strikes an arc onto the edge of the hole and you simply fill across the hole without actually welding down to be lower layer of metal, or at best only make very inadequate penetration.

It is for that reason that nowadays I always use a 5.5mm drill hole which makes it easier to strike down through the hole to the lower layer of metal and then fill up to the top layer.  

No doubt my age related reduction in eyesight acuity does not help but it is still something to be aware of.

Ted

[Clive]

that one I linked to is a tama one (at least the photo is!) which is what I have owned for 20 years.
Sadly I lost the spring ages ago, but still functions extremely well.

[1967 MkIII]

Thanks JensH   I'll start with one panel and see from there whether I'll continue myself or go to the pro's!

Clifty - i meant to add this link but in jest :) I'll go for the Tama as u recommend  http://www.mankymonkeymotors.co.uk/Misc/joddler/words.html

[Clive]

Don't jest. There was a story about a bloke who had the idea and made a joddler using a pair of mole grips. He lent it out, and a few months later somebody else took a patent out on the idea. Coincidence? but it is possible to make your own. The real gem is the hole punch though.

[Sheepy]

I have the hole punch tool, saves time and effort compared to drilling, and as said does not need dressing where the drill bit goes through you always have a burr to clean!

As for the panels, firstly, get as many mole grips as possible, then position the panel, clamp it well, check the fit, adjust as necessary before welding

If you check out my thread "mk2 restoration" you will see pictures how I did it.

Be prepared to adjust replacement panels, even heritage ones!  :-/
Any other help just ask, we will gladly give advice.

And don't forget, take plenty of pictures and start a thread, we like piccy's.

[1967 MkIII]

Wow Shaun that's an excellent job you're doing, well done! I now wish I hadn't left Luxembourg as you would have been volunteered for another Mk3 project  :P

Steve

[Sheepy]

Cheers Steve, I enjoy doing it.

Next one is also a mk3, but first will help dirk on the rebuild of the mk 2.  ;D