1998 Mini Cooper. Strip to the shell rebuild

[-ghost-]

You got it

You could get the bead a little closer in places but the penetration looks good

I'm sure spice will be along to give some expert advice

[spice_weazle]

Its looks good Pete. Im going to try and explain something but cant think of how to put it into words so tell me if it makes no sense at all.

When you do a blob/tack it glows red hot for a while, yep. Whilst it is still glowing get a blob/tack next to it but try and over lap the the new tack onto the previous one a little. If your timing and position is right the new blob/tack will fuse with the previous one because the first hasnt cooled fully. That way you will get a nice neat and strong weld. Does that make sense.

Edit:-

Looking at previous posts its just as Mike41288 has said.

[Petrol]

Got it Thanks for your help, very much appreciated. I was beginning to worry that we couldn't fix the shell up

[diamondsink]

What gas are you using? Make sure the metal is clean as possible. It looks like you are getting a reaction in the centre of each weld tack, like its reacting and oxidizing creating a hole.

[Petrol]

CO2 but when the bottle runs out I will get an Argon / CO2 mix. Sometimes the wire sticks to the weld, is this a setting / operator error?

[nismo]

Pete, If you go on BOC online they do small bottles off Argon shield gas which is a lot better than CO2. Plus the bottle rental is reasonable now.

You will need a gas regulator for this which are available on Ebay cheap.

If you are doing a lot off welding its the best option.

[LED sandwich]

For gas i would get a rent free bottle, mine was 60 deposit then 45 a refil for 200 bar 10l cyllinders of 95% argon. There are a few cheaper places but i went for the most local to me.

[Petrol]

Thanks for your help guys but I am hoping it won't need that much mig welding - hoping big time TBH. Most of it will be spot welded with a bit of luck.
Santa came today and brought Mike a pair of air horns, I wired them up and they are so cool! I want some for my S13!

[LED sandwich]

Ha Ha good work mate, mig isnt too bad as long as you get everything clean. and wel thats your specialty so im sure youll be giving everyone else tips in no time

[Petrol]

Thanks for the tip LED sandwich, welding isn't my strongest point but I am getting better.
Been over to the Minisport shop a few times to pick some bits up and being the petrolhead I am, walked in to the garage to have a chat with the mechanics in there... Have to say they are a great bunch of guys and always happy to help. Mucho impressed with the standard of work and every time I pop in, they say hello. Popped in a couple of days ago and was shown this



This is a genuine Austin Cooper works built rally car. Came 2nd in the RAC rally (really showing my age here)

Dash



Drivers seat - no head rest in this era, these drivers were brave



Toolkit, also check out the mickey mouse cage



Engine bay



I appreciate the Mini is not everyone's cup of tea but what a piece of history

[LED sandwich]

That is epic,

[The Roadie]

Lol MPi Minis ('96 on) are even worse for tinworm, they only painted the bits that you can see!

What panels are you putting on? They vary massively. Tbh me and my mates switched from genuine to M Machine panels a while ago as they seem to fit better and last longer. My genuine outer sills fitted like a glove though, much better than spurious ones.

Minis are ace!

[Petrol]

I'm mainly using Magnum panels, I have found a cheap supplier locally. I have however bought a genuine heelboard (that's the back bulkhead)

It needs a lot!

Front panel
Wings
Bonnet lip
A panels
Door skins
Rear 1/4's
Boot skin
Rear wheel arches
Rear valence
Roof skin
Inner and outer sills
Door steps
Rear subby
Dash upper rail
Scuttle panel

That's just so far! It's gonna be a total shell fabrication.

Not done so much on the shell but the rest of it has had a good going over





Rust in the seams of the boot



Frame is salvageable but needs a lot of work



Door frame prepped



Usual stuff, lots of shiny paint and stainless

[The Roadie]

Lovely work mate.

[Petrol]

Lovely work mate.

Thanks, The shell is my main concern though. I don't have much experience of sheet metal fabrication I'm sure it will get sorted though. I have a plan to coat everything with zinc, a bit like like an E coat but with zinc, this will be followed by a good dose of Dynax and should stop the tin worm.

[spice_weazle]

You will be fine with the fab work. Your no daft lad and there is no better way to learn than having a go IMO. I find the hardest bit a lot of the time is cutting the bad metal out because its the unknown of whats behind it. You have to go carefully because you dont want to cut into good metal. Putting new metal on is far easier IMO.

[59bhp]

can you buy replacement shells?

[Petrol]

Thanks Spice


Replacement shells are £6K. The problem is, they are bright steel welded up and primed. This means rusty spot welds inside the seams. You can't have em E-Coated either (another £2k BTW) as the seams are too wide. Process goes like this

Acid dip to remove everything including rust. Remember the minute you weld it's rusty and you can't e-coat on rust
Rinse tank to get rid of acid
E-Coat

Problem is, the seams are that wide that the rinse tank doesn't get rid of all the acid so you end up with acid in the seams. It's catch 22. The only way I can think of building a shell that won't rot is to force Electrox into the seams with compressed air. I tried this on a test plate and it worked. I managed to force the thinned Electrox right around the spot welds. When I fit the door skins I am planning on painting neat Electrox on both the door and skin and knocking the fold over whilst the Electrox is still wet. I will then plug the drain holes in the bottom of the door and pour in thinned Electrox before draining. This should ensure everything gets coated.

This is one of the door skins prepped - inside. A new shell wouldn't have this standard of prep




I will also be using seam sealer and once the shell is painted, I will give everything a good dose of Electrox

It's proving an interesting build

[The Roadie]

can you buy replacement shells?

Yes you can. As already mentioned, they still rust. Plus, I've never, ever seen one that looks right. Usually the doors just don't line up with the rear quarters and/or splay out at the bottom.

It's a much better (but massively time consuming) bet to do a thorough job like Petrol is doing.

[59bhp]

Yes you can. As already mentioned, they still rust. Plus, I've never, ever seen one that looks right. Usually the doors just don't line up with the rear quarters and/or splay out at the bottom.

It's a much better (but massively time consuming) bet to do a thorough job like Petrol is doing.

Thanks Spice


Replacement shells are £6K. The problem is, they are bright steel welded up and primed. This means rusty spot welds inside the seams. You can't have em E-Coated either (another £2k BTW) as the seams are too wide. Process goes like this

Acid dip to remove everything including rust. Remember the minute you weld it's rusty and you can't e-coat on rust
Rinse tank to get rid of acid
E-Coat

Problem is, the seams are that wide that the rinse tank doesn't get rid of all the acid so you end up with acid in the seams. It's catch 22. The only way I can think of building a shell that won't rot is to force Electrox into the seams with compressed air. I tried this on a test plate and it worked. I managed to force the thinned Electrox right around the spot welds.

that's annoying, want to build a mini at some point but was hoping you could just buy a completely rust proofed shell off the shelf

once the 200's done im pretty sure i will be done rust proofing things from then on