View Full Version : Spitfire Spitfire Panel replacements - welding tips

09-09-2003, 10:57 PM
I've got to replace my sills, my boot floor and clean up the a posts.

Should I buy a MIG welder or do gas? Someone told me Gas offered more control and was gentler to the metal.

Anybody know what's best? Do you think that the guy meant gas - as in butane torch - or oxyacetylene?

My other option would be to hire a spot welder.

I've got a lot of work to do - as you can see on my site at the bottom of the page - so I should buy something suitable to use.

09-09-2003, 11:51 PM

I would use a stick welder or spot weld it. MIG welding is much more difficult, and I am assuming you are not an experianced welder. Gas welds are very problematic unless you are good at it. The torch (oxyacetylene) will take any temper out of the steel. Then you will have the steel around the weld break out very badly. My advice would be to hire someone to either spot weld it or MIG weld it, or get some scrap steel and practice alot with a stick welder or spot welder before messing with your sills and pillars. Hope I could be of some help.

Cheers, graemlins/thirsty.gif graemlins/driving.gif

P.S. I'd also use 70 18 rod for sills

[ 09-09-2003: Message edited by: waltesefalcon ]

[ 09-09-2003: Message edited by: waltesefalcon ]</p>

09-10-2003, 12:20 AM
Good question. I've had quite a bit experience in fixing up the body panels on my TR6. I am using an old Miller 130 Mig welder. It uses a gas mixture of CO2 and Argon to shield the weld arc. I picked it up at a pawn shop for $100. Add to that a $28 spool of wire, a gas bottle, a helmet and I was ready to go for around $250.

Someone had shown me a way to "stich" a patch piece in place - using the lowest welder setting. That is putting small spots 2-3 inches apart at the point the patch and body meet. I use and overlap method with the patch. Make sure they are both VERY clean. I then go back and fill in the gaps with more spot welds. I end up grinding the spots down smooth(using a grinder with a flapper disc). I haven't mastered the ability to use lead so I use bondo to fill in the irregularities.
I bought a new fender early on and used the old rusted one as the source of metal for my patches. Needless to say there's nothing left of the old fender.
For me the MIG has been very useful - especially with the 4 power settings it has available. I would not have ever been able to tackle this project without a welder - of any type. The previous owner had used rivets and they looked like junk - and they worked loose too!
I also found an air hose has been useful in blowing out those small fires that can erupt while welding away(so much for undercoating).

Good luck,

09-10-2003, 02:56 AM
Hello BCF,

Do not (sorry Waltese) go anywhere near a stick welder for body panels. You will just burn holes as they are too strong. Most amateurs use a MIG, as they are relatively cheap and easy to use. (The principle is exactly the same as for stick welding, strike an arc and go along.) Gas (Oxy/acetylene) has some advantages, namely the weld is soft and on butt welding of outer panels, there is little metal to remove after, unlike a MIG which leaves a hard bead. You won't take the temper out as mild steel does not take a temper, or harden with heat. There is, or can be a lot of distortion which makes it a difficult method in some instances, particularly long seams on panels with not much shape.
A spot welder is perfect if you wish to replace complete panels but not much use for patch repairs or repair panels. In an ideal world you would use all three systems.
Gas, by the way, is the most versatile, as it is useful for other things like freeing seized bolts, brazing heavy section pieces. Gas is what I have used for 20 + years, I also have a stick set for heavier fabrication.
Whatever you get, get a book for guidelines and practice on some scrap metal first.

Good luck,

Alec graemlins/cheers.gif

09-10-2003, 03:13 AM
I've got arc welding gear that I use for joining heavy **** but I know that this is totally unsuitable for panel work. I am an amateur at welding and intend to take my time here.

I will be patching holes and also replacing entire panels.

[ 09-10-2003: Message edited by: britishcarfreak ]</p>

09-11-2003, 01:09 AM

No need to apologize to me. You are much more experienced than I, and so I shall defer to you. However I would like to say that I have never had any problems with burning holes in sheet metal with a stick, though it did take quite a bit of practice to get to that point. And I would still pick MIG over Gas, but I do agree that Gas is the most versitle way to weld.

Cheers, graemlins/thirsty.gif graemlins/driving.gif

09-11-2003, 03:20 AM
Hello Walter,
I take my hat off to you if you can weld car gauge steel with a stick welder.
I bought an attachment for my arc welder which was claimed to make welding thin gauge steel practical. (Basically a diode) Even with that and 1\16" rods it was a hassle so I gave up. (I was looking to reduce the distortion problem that I find with gas.)
I don't know about America, but our Technical Colleges run courses aimed at 'hobbists', e.g. welding, car maintenance, even a handfull actually run car restoration courses. Ideal if you want to learn a new skill and try the different tools and equipment available.

Alec graemlins/cheers.gif

[ 09-12-2003: Message edited by: piman ]</p>

09-11-2003, 11:39 AM
My momma always told me I was special. Now I know why graemlins/thumbsup.gif

Cheers, graemlins/thirsty.gif graemlins/driving.gif

Simon TR4a
09-11-2003, 12:10 PM
Just to take this in a slightly different direction, I know of a pair of Spitfires locally for sale for about $1000.
Both were running within the last year, the better of the cars needs floors and sills, and various other bits which should be salvageable from the parts car. It would then need painting.
Since neither car has overdrive I felt this wasn't financially viable, what do you guys think?

09-11-2003, 08:06 PM
well each type of welding has its advantages(well maybe not stick on light gauge metal, yes i have done this, got suckered into it but the i got the last laugh it worked!)
when you weld you will have shrinkage!!! now underside/inside it is not as important(cosmeticlly) so a mig or tig is fine, if you really got to stick also!
but for outer surfaces oxy/acetelene is much nicer. if you work at it you can join the 2 pcs
and hammer smooth, not need any bondo or lead.
this take time and experience but can be done.
alot of people mig it together and bondo it up,
heck they glue newer cars together! a overlapped
replacement panel glued properly will be as strong
as the orginal(according to the glue guys maybe its the fumes!) the easiest one to learn is mig
a couple of adjustments of heat and wire speed,
enough gas(have not use flux coated wire) and make
it sound like bacon frying your welding!

Take care!
good luck with your project!