Alfa Pages

[LDA]

hey all,

i have been changing my mind as to what to do with me p4 for a few months now. i've now chosen to convert it to rear wheel drive only and stick another engine and gearbox in there from a mazda RX7 fc(the 80's shape)

the rear of the car is going to be chopped about to fit the rear axle, shocks and diff from the rx7. i have had a chat with my local independent garage (who race bmw's) and they have given me a quote to make the changes to the chassis. but they said that due to the extra power of the turbo rotary lump, that i should get the chassis seam welded.

i have never welded before. and the quote jumped up from a few hundred quid to much closer to 2k with the seam welding. this is because its loads of labour.

is seam welding a diy job? and would it be possible for me to learn how to weld on one of my spare cars in a short enough time to be able to weld up my 33?

also, you racing lot must know about roll cages. are there any cages off the shelf for the 33? (mk3)
i dont mind if its a bolt in or a weld in but i do want door bars and at least one diagonal support.

thanks in advance,

Luke.
_________________
A good workman allways blames his sh*t tools.

[dave]

hi luke hows it going
still looking out for p4 shell for you shame cut -change your good one
fancy going racing sunday 13march at brands plenty of 33s you may be able to ask the racers themselves re welding and roll cages thanks dave
_________________
alfadave1@btinternet.com
VW TOURAN 59 PLATE WHITE WITH TINTED WINDOWS AND ALLOYS MR BLING
CHEVY MATIZ

[LDA]

hi dave.
i'm in canada for 2 weeks as of saturday. sad to miss the raceing but to make up for it i'll be snowboarding in fernie

but asking the racers is a good idea. i spose some of them (if not most?) must prepare their own cars.

L.
_________________
A good workman allways blames his sh*t tools.

[Eddie W]

Hi Luke, seam welding is done with a MIG welder and I wouldn't recommend tackling the car without a fair bit of practice. It's very easy to blow through the floor if you don't know what you're doing. You should be able to cut a fair bit off the cost of a professional doing it if you did the cleanup prep yourself. The seams have to be absolutely clean of paint, underseal and any other contaminents including the paste they often put between the lips that are spotwelded. The welding itself shouldn't take more than a day at the outside if the guy knows what he's doing. I've done them in way less.
Don't for one minute contemplate gas welding or you'll distort things to buggery and run a good risk of a fire.
You need to determine which seams are crucial and what areas would benefit from plating or gusseting. These would need the same cleanup and you could fabricate the reinforcements yourself.
Also that would be the time to brace the engine bay from firewall to front panel.
Regards Eddie
_________________
A LITTLE FURTHER A LITTLE FASTER

[LDA]

hey eddie,

thats for that. i think that i'll go have a chat with the local body shop and ask them if DIY prep would bring the cost of the job down a lot. i have never welded before so i doubt that i could do a tidy job on my car. best leave it to the pro's.

i have found out that the local college does evening welding classes though. its a 3 month course so i might sign up for that to learn for the furture.

L.
_________________
A good workman allways blames his sh*t tools.

[ChrisC]

welding isnt magic. I learnt to weld on the fly and it didnt take much time at all, and if youre only reinforcing existing welds by seam welding its easy as pie.

Most of the cost will be removing / refitting the interior, so do that yourself if you want to save money.
_________________
Alfa Sprint QV - Gone to a better home and in happier health for it
Silver Lancia Beta HPE Volumex - under restoration

[Eddie W]

Hi Cris, Iv'e only been doing it for the past 35 years and I've seen an awful lot of crap MIG welding , some of it by so called professionals. It is fatally easy to just lay down metal with no penetration, especially if welding overhead as required for seam welding. A MIG welder is a constant voltage machine as opposed to a constant current arc welder and stickout, position and wirefeed speed all vary the current and the resulting weld integrity. I'm not saying it can't be done by amatuers but some practice and training would greatly improve the result.
I've seam welded, rollcaged, turreted, 4 linked and done just about every mod you could think of to rally and race cars and I know whereof I speak.
Regards Eddie
_________________
A LITTLE FURTHER A LITTLE FASTER

[johnboy]

Hi eddie

Your right, its a big job. i do all the welding on my car, ive just done aload on the passenger side sill,started to jacked the up, jack went up,car stayed on the ground, not good! a little hole turned into a big one!! i've got better with time, you know when you've got a good weld by the sound, i think eddie will understand what i mean? plus we all need good penetration

regards john
_________________
WODA WE NEED? MORE POWER!!

Alfa gt jtdm blackline
1990 S2 16v veloce sleeping!
2002 ts gtv the wifes now
1997 seadoo gsx 800
1999 freestyle superjet

[paddy granger]

[ChrisC]

Its very obvious by the sound when you arent getting a good weld.

That said, judging by the expertise my mechanic has shown welding on my sprint I would say that you can be competent but still have a long way to go!

I recommend practising with some sheets of scrap / repair steel before going near your car.
_________________
Alfa Sprint QV - Gone to a better home and in happier health for it
Silver Lancia Beta HPE Volumex - under restoration

[Eddie W]

Indeed John you are correct, the sound tells it all. It's hard to describe what it should be like but a smooth buzzing crackle is about the best I can think of. If it sounds like bacon in the frypan it has too much voltage, if it runs in fits and starts with the wire trying to push the gun away then the voltage is too low. When the voltage is too low the weld has a high humped profile that sits on top of the base metal and too high a voltage will produce a flat weld with lots of spatter. Any residues that can burn(ie paint, underseal etc) will contaminate the gas shield and act generally as though the voltage is too high as well as produce porosity which seriously affects the weld strength. I'm not suggesting you guys don't undertake it because I think it's a bloody useful skill for a car enthusiast, but a little practice under supervision would save a lot of heartache.
Warning : disconnect the battery before welding as the diodes in the alternator take exception.
As an aside I've had MIG welds tested to 90,000 lbs tensile without failing and welded 1" thick plate ( with suitable V prep) in a single pass with a MIG welder and achieved full penetration. This was using the welder in what is called "spray transfer" mode.
Regards Eddie
_________________
A LITTLE FURTHER A LITTLE FASTER

[Eddie W]

Addendum to the above . It is a little like frying bacon but I think what I'm trying to say is that if the welding has a really" fatty" sound then the voltage is too high.
Regards Eddie
_________________
A LITTLE FURTHER A LITTLE FASTER