Making panels.......

Decided to chop the whole thing off instead of trying to bodge it in situ. Glad I did, as the firewall was worse than I hoped for.





First patch is in, hope to find some time in the coming days to finish the firewall, repair the air box and put everything back in place. Thanks for looking!

Hi, Melle. Your Saab need own thread on to the Reader Rides, because We here in RR love good weldaton threads, specially if it's done to a interesting car like Yours.

But still, Looking good.

That's often the case though - I made some small repair sections for my boot floor, and recently discovered that some of the parts I thought I'd get away with also needed replacing, so it would have been neater to do it all in one go instead. That said, on the first repairs I also had to consider not cutting out so much that I lost the structure of the car, so a number of early repairs are several pieces where one would have been nicer.

OK heres my dilema, I have recebntly removed the Rear Subframe on my Austin Mini in order to complete some repairs I have already started in the boot. On removing the Subframe I noticed some tin worm holes!!

I have stripped the the Subframe to get a better look and it is worse than I thought.

I need some advice on whether it can be repaired and if so how?

Most of the rot is on the bottom rear of the main spars that run back to front as these are the areas that hold the water. Looking at the fantastic advice in this thread, these parts should be easy enough to fabricate and replace. There are however some parts that need renewing that look very hard indeed.

Here's the complete stripped subframe:



This is the RH top skid plate of which the front end at least needs to be replaced:



This is the LH top skid plate which also needs the same treatment:



This is a view of the inside RH main strut which looks a relatively easy part to replace:



And here is the rear of the same main strut:



The other side of the same strut is not as bad but does need repairing at the rear and the outside LH main strut also needs repairing at the rear and towards the front, as seen here:



And here is another (better) view the inside RH rear bottom strut:




Now here comes the tricky part.

The mini rear suspension consists of a radius arm on which the rear wheel drum is fitted. The bumps are absorbed by both the rear shock and by a rubber cone that sits in a cup in the rear subframe attached to the radius arm by a rod (trumpet) knuckle joint. 
The rubber cones I think (not sure) have a metal rim around the base which sits in a cup which in turn is welded to a support plate?
The cups (if that's what they are called) are welded in a recess toward the rear of the subframe, one side is pretty bad and the other could also be part replaced. the worse side actually came apart when was a little over ambiguous in removing the trumpet and cone.  

In the following pic I have put the trumpet and cone back in position to give you an idea, the other trumpet is just there to hold it in place temporarily:



And here's the knuckle end that would sit in the radius arm if it where in place:



Here are the two cones, the RH one in the pic is the LH cone on which is the metal cup that ripped out, looks like it may have been spot welded?



Here is a pic of the base of the rear cone support that appears to sit on a support piece located on inside of the bottom and the top main strut. This pic shows what it should look like (apart from the main cup which ripped out) the top support in this pic is rotted as is the support piece that it sits on. Question - how on earth will I replicate this circular cone cup support?

 

And here is another pic of the support piece that sits on the top and bottom plates in between the main struts:



And here is a pic of an intact (but badly corroded) cup, once again how on earth can I replace these?



And here's a pic of a corroded support piece and cup support that will need replacing:



Questions:
Is this bad boy repairable?
How can I make the various circular pieces in the pics above?
Should I get it shot blasted before I start or just attack the parts with a grinder (twisted knot attachment)?
If and when I do start to repair it should I brace the Subframe before I start cutting bits off of it? E.G. weld some support bars between the front and rear cross members to prevent the subframe from getting distorted?
Should I do small parts at a time to avoid distortion?
Should I just cut out the rusted parts or try and make complete parts using a larger gauge metal?
Is there a list of recommended minimum sheet metal fabrication tools? 

Sorry for the uber long post and dumb ass questions but help would be appreciated :-)

P.S. Here is a pic of what I hope it will end up looking like, in this pic the guys has fitted an adjustable Hi Lows? instead of the standard trumpets, interestingly the metal ring around the base of the rubber cone looks like it has been replaced so maybe I don't need to make at least the large circular bits that the rubber cones sit in? I'll ask on a Mini web site to be sure and confirm what is and is not part of the subframe.

 

I get what your saying however I don't have the cash for a replacement and with regards to the legality I started a thread here and a reply from Hotrodder with references to the regulations suggests that it is OK. 

I think as long as you have some basic skills, it is worth trying to repair the one you have, especially if you have some welding skills. Right now, you have a mini subframe that is worthless, so you can't really lose a lot by trying to sort it out, and you'll gain experience however it pans out. Some of the parts that you need to sort out will be quite easy to make and fit, some will be more challenging.

First thing is to get that subframe stripped down. If you can get it blasted, then do so, failing that clean it up with a selection of whatever you can get. A grinder with a twisted wire cup will make short work of a lot of the weak metal, but you won't get it into the corners unless you've found a very small one - and if you have, tell me where please as I could do with one. Watch as you work with the wire cup - if it catches an edge it will jerk and can cause quite nasty injuries. Also you could look into electrolytic rust removal - that's a nice passive way of cleaning rust off and can work very well.

Pay a lot of attention to how you cut out the bad sections and weld the new bits in. In particular if you're going to do the easy bits first, make sure that once you've welded your repair in, it doesn't block access to one of the harder repairs - there's nothing more annoying than doing a nice repair job, then having to cut it out again because it's the only way to get to another section. Take a lot of measurements and photos, and if you can make some sort of jig to reference the important parts, that would be a good thing to do. As for what tools you need, you'll soon find out when you need to make somthing. Looking at a thread I posted some years back, it seems it's possible to do anything with a hammer and a big piece of wood, but maybe also need a lot of experience.

In your second to last photo it looks as if the subframe has already been repaired, I would think your new welding will need to be better than that was done. As for your question "Should I just cut out the rusted parts or try and make complete parts using a larger gauge metal?" I'm not sure what you mean - to repair this, you need to cut out the rust. Repairs need to be the same gauge as the original was, or maybe a little thicker - certainly no thinner - BLMCs bean-counters will have calculated the minimum thickness to save money but still retain the required strength, even back then.

Good on ya for taking that on! Even if it ends up being scrap, you'll still get some valuable welding practice out of it.

That weld you posted looks a bit cold, you should increase power a bit, or reduce wire speed (assuming you're using a MiG machine)

Cheers!

Thanks for the enthusiasm, ref the welds yup its a Clarke EN160 Mig (I think - not in the garage at the mo) I could crank it up a notch.

Tony / Anyone?

I am going to build the tonybmw bender next week and may opt for the sizes in the plan i.e. around 1/2 metre wide however before I do go firm on the sizes can someone help with this question:

I will be making some inner sills for my Mini, I have just measured the length and they will be about 130cm long - would his bender be ok for this kind of fabrication or do I need a metal brake?
I may be able to borrow a metal brake at work so it might not be a problem however for future reference, can you bend panels longer than the bender or a folder, i.e. do a little bit at a time?

Whilst I was typing this a solution just popped into my head.

If you build the tonybmw bender (Or any bender / folder) to the width based on (a) Your workbench and (b) if you want to be able to transport it. Then in order to cope with wider panels just have a couple of extra long loose pieces of angle iron wide enough to take the panels. Open the bender and Insert these additional pieces of angle iron and clamp in you panel. If the panel is particularly wide you could also clamp either end of the additional angle iron with G Clamps.

Same principle for lifting an extra deep pallet with a Fork Lift - just add fork extensions.