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Old 3rd July 2018, 09:31 PM   #1
harrypevo
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Default Another e36 rescue / resto thread, includes welding...

I wasn't going to post any of this initially, I wasn't sure I wanted people to see how bad it was, but I'm proud of how it has gone and how it has turned out and thought people might be interested. I'm sure there are 'better' ways, I'm sure many will wonder why bother, but it's my car, I want to keep driving it and I kind of wanted to see if I could do it.

I knew I had a few rust issues simmering under the surface, I had done a couple of temporary fixes to buy myself some time.

With the mot looming in November I had a couple of weeks in September put aside to sort it ready for winter. Then I spent one of those doing a clutch on the mrs' car and realised I probably wasn't going to get it done in time so concentrated on getting my blue 316i compact back on the road to use through winter.

I soon realised it probably wasn't going to survive long term and was so slow I hated it. Fine as an occasional runabout, not as an only car. Which is where my silver 318ti came in.

As winter dragged on and on I managed to get a few bits done to get it looking and handling as I wanted inbetween the weather knowing I wasn't really wasting any time I could have spent on the m3 as it's issues weren't quick fixes.

So, a few weeks ago I got started. The only outward signs of an issue were a couple of bits of seam sealer in the engine bay lifting and a couple of rust stains breaking through.

Scraping off the seam sealer and a slight prod with a screwdriver revealed this



And removing the arch liner and giving the underseal a prod...



The small round hole is a drain hole, in the middle of the square hole is where there should be a little plastic plug to hold the arch liner up. It's a common rust area, the blue compact is starting to go in the same area


Having a feeling it would be pretty bad when I started digging I had already chopped some donor panels out of a compact someone local was breaking ( before I had decided to break mine )

So started drilling out the spot welds to see how the sections were pieced together.



There's the upper rail ( which the wing attaches to the top of ) the turret and the closing panel which forms the main tub of the inner arch, and wraps around the inside of the turret and is welded again along the side.

I didn't want to use the entire turret as it would need the engine to come out, plus there would be no way without constructing some sort of elaborate jig to be able to guarantee maintaining the original geometry.

Thankfully my upper rail was perfect which meant it wouldn't have to be cut and would be a fixed reference point, I would then chop sections out of the turret a piece at a time only cutting out the minimum unneeded to to completely remove the rust.

I made a rough cut to the under panel just to get it out of the way, it could be neatened and trimmed back later.


And chose the first section of turret to remove. I picked the rear corner as it was already corroded through in the corner and not really doing anything to support the rest of the turret anyway.



With that welded along its back and top edges and through the spot weld holes to the rail I could move to the next section which needed a far higher cut.


I literally just skimmed the top of the rust ( upper right of this section ) there would be a piece behind which is why it's gone through the rust on the left side.


New piece cut trimmed and clamped


And stitched


Onto the next section, daylight is never a good sign,


This was where there was a telltale rust stain bursting through the paint. Thankfully I was able to start cutting back in towards the seam.


The last piece, just needed a small section of the turret flange, but a larger chunk of the inner wing as there was some rust behind the brake pipe bracket, those two spots are where it was attached.


And from inside


Frankenstein


With the turret solid and stable I could trim the inner tub where I wanted it, and trim the donor tub to suit


Which was then plug welded through the drilled put spot weld holes from both underneath and on top, and given a tickle with a grinder



Being impatient I gave it a squirt with an aerosol to make sure the general shape was ok and whether any bits would need more work.


I then asked a mate who does repairs for a living what he used for underseal. He showed me a nice wurth gun, I did some reasearch and decided it was way out of my budget. Handily he had his old gun kicking around which he sold to me along with some sprayable sealer.

I used the underside to practise, and tried to replicate the original ripple finish.


And decided it was time to bite the bullet, mask it up and spray the visible seam inside the engine bay.


Which has to be painted within 4 hours to ensure a proper bond with the sealer, so mixed up a little paint I had spare and gave it a coat ( this is purely to colour the seam and won't be the final finish )



A lot of it won't even be visible once the wiring, washer pipes, washer bottle etc are back in place


And that is how it sits at the moment.
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Old 3rd July 2018, 11:33 PM   #2
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fair play dude, that was pretty grot, and the repair looks sound enough.

Not trying to pick holes, but what is the condition of the rest of the body?
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Old 4th July 2018, 08:15 AM   #3
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I little frilly around the edges, but nothing major. It's had a couple of sections of sill under the jacking points and a rear arch but that's about it.

I've had all of the rear end, the gearbox and all liners and covers off at some point over the last couple of years so have done plenty of poking and prodding around.

A reshell would probably be a better idea, especially as you still see the odd clean saloon, I just don't really have the space or time to do a full swap, and it would no longer be an m3, and it wouldn't be 'my' m3.

I'm trying to save it because I want to, not because it makes sense to anyone else.

Plus I would like to see it make 300,000 miles, just as a personal goal as everyone else seems scared of cars with 100,000 on them.
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Old 4th July 2018, 09:50 AM   #4
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Quote:
Originally Posted by harrypevo View Post
I little frilly around the edges, but nothing major. It's had a couple of sections of sill under the jacking points and a rear arch but that's about it.

I've had all of the rear end, the gearbox and all liners and covers off at some point over the last couple of years so have done plenty of poking and prodding around.

A reshell would probably be a better idea, especially as you still see the odd clean saloon, I just don't really have the space or time to do a full swap, and it would no longer be an m3, and it wouldn't be 'my' m3.

I'm trying to save it because I want to, not because it makes sense to anyone else.

Plus I would like to see it make 300,000 miles, just as a personal goal as everyone else seems scared of cars with 100,000 on them.
Fair play. Ultimately for a car with the sort of miles that yours does i would do the same, just keep the old girl running. You enjoy the car, why not save it. if its still running well at 300k maybe thats the time for the re shell, until then just keep it rolling.

Good luck
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Old 4th July 2018, 10:05 AM   #5
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That looks like a really nice (and patient) job to me.
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Old 4th July 2018, 10:51 AM   #6
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Wow that's a really good repair mate and fair play. Mine would have been scrapped at that point so bloody good show mate.
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Old 4th July 2018, 12:23 PM   #7
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I doff my cap to you sir, great job. I think you successfully answered your question; can you do it? - you can!!
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Old 4th July 2018, 02:52 PM   #8
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Very nice job
Also the use of intergrips I've always found a challenge as in car thickness steel with MIG root gaps tend to lead to blow through as it oxidises from the reverse.

Welds look very good too, what MIG are you using
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Old 4th July 2018, 03:19 PM   #9
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Great work! I totally agree with keeping the chassis as an M3 chassis like you have done.
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Old 4th July 2018, 04:42 PM   #10
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Trouble with some cars is they reach a point where there are too many holes to spend the time but jointing in repairs, especially if you are making the repair sections.

For my E36s the visible stuff I spend more time than the less visible, for example my 328 has sideskirts so the back 18" are 1.6mm plate with rear wheel bearing inner races welded on as the "jacking puck"
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Old 4th July 2018, 05:50 PM   #11
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I really wanted to butt join the turrets as it would be so visible whenever the bonnet was open, they're also really nice thick metal ( when not rusty ) so was pretty easy to get a good strong weld, I welded both sides too to make 100% sure they were full thickness.

The closing panel was harder being really thin, especially once ground to remove paint near the weld edge. I usually have to do them as a series of spots joined together which isn't very pretty but cleans back ok. My seam sealer line is just slightly thicker than the standard one was as I had to cut just past it to make sure everything was removed. On the bulkhead side I was able to keep it all under the sealer line.

Bits like under the jacking points I will just cut back to ensure all the rust is removed and use a slightly overlapping panel, up to a contour line if possible then self all the edges and grind back to a smooth lip. I try and copy the factory attachments where too, copying the original spot weld points, or put a stitch weld in.

My welder is just a Clark mig with gas which I've had for about 15 years, I'd like to upgrade, but they all seem to have gone up a lot. I'm sure I payed about 140 for it at the time but an equivalent now seems to be well over 200.

I remember when buying it I bought a couple of models up from the most basic not for more power but because it's lowest setting was lower than many others. Even then it's still very easy to blow through.
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Old 4th July 2018, 06:47 PM   #12
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^ That's pretty much normal then. Sounds like the turrets are chassis section thickness.

TOP TIP: These get paint and sealer off quickly without thinning the metal and without getting paint hot and smearing
http://www.rightlines.co.uk/Strip-Cl...ing-Discs.aspx
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Old 4th July 2018, 09:59 PM   #13
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Fantastic, wish I had the skills!
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Old 5th July 2018, 04:36 PM   #14
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Quote:
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Fantastic, wish I had the skills!
Nobody does before they start doing it inspite of that
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Old 5th July 2018, 05:14 PM   #15
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I have no training and only mess with cars as a hobby, and certainly no expert, just not afraid to give things a go.

My method is what suited me given the tools I have and what worked logically in my head. I'm sure you could give ten different people the same starting point and get ten different ways of fixing it!

There is a certain amount of confidence you need in your abilities to fix it if you mess it up, but I started with a rusty car and the end goal was a less rusty car. If it had all gone horribly wrong I probably would have had to reshell it which would be the same thing I would have to do if I didn't want to weld it.
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Old 5th July 2018, 05:19 PM   #16
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Quote:
Originally Posted by harrypevo View Post
I have no training and only mess with cars as a hobby, and certainly no expert, just not afraid to give things a go.

My method is what suited me given the tools I have and what worked logically in my head. I'm sure you could give ten different people the same starting point and get ten different ways of fixing it!

There is a certain amount of confidence you need in your abilities to fix it if you mess it up, but I started with a rusty car and the end goal was a less rusty car. If it had all gone horribly wrong I probably would have had to reshell it which would be the same thing I would have to do if I didn't want to weld it.
If it had all gone to poo you just bolt a plate inside the turret for alignment, weld box sections from it to the chassis rail and A pillar to triangulate the. Drill out standard spit welds and drop the whole panel off and replace as you have provided a jig
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Old 5th July 2018, 05:59 PM   #17
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One comment about zinc / weld through primer
Anything you can scratch off with your nail Ian not a sound base for others coats
Mig still sees it as an impurity in the weld
Great for soaking seems 2 or 3 times till full by capillary action though so air and water can't get in to cause rust, clean off the excess and use proper paint
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Old 5th July 2018, 06:23 PM   #18
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Where large areas are covered in it I'm just using it as a temporary rust proofing, as the car is stored outside. I wipe surfaces down with thinners before using a proper coating, which just leaves it in the seams etc.
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Old 5th July 2018, 06:28 PM   #19
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Quote:
Originally Posted by harrypevo View Post
Where large areas are covered in it I'm just using it as a temporary rust proofing, as the car is stored outside. I wipe surfaces down with thinners before using a proper coating, which just leaves it in the seams etc.
That's the way to go
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Old 7th July 2018, 10:20 PM   #20
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Good work mate. I had similar repairs to carry out on my own strut tower. Lower down where the tower and chassis leg meet. However I didn't have the skill to carryout the welding myself.
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