Time for an overhaul of my 1.9 '98 BMW Z3 Individual

[IainP]

Squirt some hot waxoyl in there before you paint and reseal it.
If you’re tempted by s/h migs Matt completely discount SIP Migmates, or BOC Turbo migs, they’re rubbish, hopelessly inconsistent wire feeds.

 

[Matt Barnes]

Squirt some hot waxoyl in there before you paint and reseal it.
If you’re tempted by s/h migs Matt completely discount SIP Migmates, or BOC Turbo migs, they’re rubbish, hopelessly inconsistent wire feeds.

Cheers mate..... I've seen some 100A flux core welders on Amazon "fitted with 13A plug"... so that's going to be my main criteria going forward !

 

[Jonno Bee]

Excellent stuff Matt. The best thing about all this effort is how much better your Zed will drive and handle when t's all done.
Keep up the good work!

Jonno

 

[Matt Barnes]

Excellent stuff Matt. The best thing about all this effort is how much better your Zed will drive and handle when t's all done.
Keep up the good work!

Jonno

thank you mate...it's a journey...and I've learnt so much already !

 

[Jonno Bee]

I sorted my Zed's rear suspension and finished the rebuild in 2020. not that any Zed is ever really finished.
Well worth the effort and skinned knuckles.

 

[Matt Barnes]

So today.. I thought I'd tackle the rear springs. Nothing wrong with them, so I took the knotted wheel and cup to them as well as the Dremel.

one on the left after a first pass....one on the right, as off the car !

far too satisfying for a grown man...

so with that done... I turned my attention the right Trailing arm to get that sheared bolt out... despite having brand new cobalt drills. they hardly touched it...I must be doing something wrong

couldn't even drill deep enough to get a stud extractor in it

so I've parked that again for a another day... options are to weld a nut on, or drill and tap a new hole.

So I turned my attention to the nearside Trailing arm.... the one I had the fight with the driveshaft nut !!!

stripped it down in half the time I did the offside one..... but...….. guess what.... despite heat, hammer, heat, hammer..... I did it again.... same nut as well !!!

it managed half a turn before snapping, so I think this one may take a welded nut

 

[Matt Barnes]

Took today off, and instead of enjoying the warm sunshine... I'm doing this !...… must say my Dad's old flexible drill attachment worked wonders getting into all the crevices of the springs

maybe a bit overkill but I treated them to a coating of POR15, which after 20 minutes, washed off and dried gently with a hot air gun. Later I'll give a couple of coats of Hammerite primer and a Hammerite top coat

Decided to have a change of scenery and peeled off the plastic and De-Ox Gel, that had I'd left on there for about 4 weeks !

so took the polycarbide discs to it... and this is where I am now ..... all looking a hell of a lot better, and welding up those holes aside, almost ready for some epoxy I reckon.

Offside Front sill

Offside rear.....

Nearside front sill.... this is as much as I can do until I brave lifting the front of the car...

Nearside jacking point

Nearside rear sill

one question I do have... the so called quick release connectors on the fuel vapour line ... how the hell do you get it off !? I've tried squeezing it, twisting it....it won't budge

To finish the afternoon off... gave the springs a coat of Red Oxide Primer.... looking 100 times better now !

Then to give me some more sill motivation... gave them a quick dusting or spray zinc primer... just to give me a feel of what they'll look like with epoxy primer on... (yes... the holes will get welded up !

 

[DrWong]

Good progress mate, keep it up!

If that's as far as you're going with the Deox and are now thinking of epoxy, I'd maybe consider the POR instead. Mainly cos there's still some dark rust pitting and epoxy tends to require bright clean steel as the substrate (at least that was the case with Lechlar, according to its data sheet).

POR on the other hand is designed to go on exactly the surface that you now have, i.e. on top of rust that isn't loose.

 

[Matt Barnes]

Good progress mate, keep it up!

If that's as far as you're going with the Deox and are now thinking of epoxy, I'd maybe consider the POR instead. Mainly cos there's still some dark rust pitting and epoxy tends to require bright clean steel as the substrate (at least that was the case with Lechlar, according to its data sheet).

POR on the other hand is designed to go on exactly the surface that you now have, i.e. on top of rust that isn't loose.

hmmm thanks mate...it's only because I left the deox and let it dry out...still willing to give it another go...I wanted to use Lechlar for the underside but if it needs bright steel, then it 's a no go...might need another epoxy in that case

 

[DrWong]

Deox gel tends to do its job within a few days. I reckon if you'd wire-brushed and reapplied the gel every few days for the last four weeks, you'd prob be nearly there now or thereabouts (sorry!)

It's the pitting that's the issue, cos if you put epoxy on top it's likely to rust through from inside to the surface. I honestly think POR is your best bet given where you are, because it's designed to go on top of and neutralise rust. Or try and find another epoxy, but I think most will similarly ask for clean steel

 

[Matt Barnes]

Deox gel tends to do its job within a few days. I reckon if you'd wire-brushed and reapplied the gel every few days for the last four weeks, you'd prob be nearly there now or thereabouts (sorry!)

It's the pitting that's the issue, cos if you put epoxy on top it's likely to rust through from inside to the surface. I honestly think POR is your best bet given where you are, because it's designed to go on top of and neutralise rust. Or try and find another epoxy, but I think most will similarly ask for clean steel

Thank you mate.... I was ready to pull the trigger on 2.5 litres of Lechlar as I wanted to do the whole underside (tank, wheel arches etc).... then go over the wheel arches in anti gravel, then top coat.... so you may have saved me a pretty penny if Lechlar can only be used on bright steel...

 

[DrWong]

Hmmm, just checked the data sheet ( Download.aspx (lechler.eu) ) and it doesn't actually state clean steel, just that the surface has been degreased and sanded.

However, I painted Lechlar over rust (remember the prestal cages I mentioned a few pages back) and the rust came back through within a year. Removed the cages, cleaned back to bright steel and epoxy'd and been fine since. From all the research I did before I sorted the sills, the general consensus was epoxy on top of rust is a no-no.

 

[Matt Barnes]

Hmmm, just checked the data sheet ( Download.aspx (lechler.eu) ) and it doesn't actually state clean steel, just that the surface has been degreased and sanded.

However, I painted Lechlar over rust (remember the prestal cages I mentioned a few pages back) and the rust came back through within a year. Removed the cages, cleaned back to bright steel and epoxy'd and been fine since. From all the research I did before I sorted the sills, the general consensus was epoxy on top of rust is a no-no.

thanks for checking mate...really appreciate it...ok..looks like PO15 metal paint for me then...dammit!

 

[Althulas]

If you want a quicker result on the pitted rust I used a stronger acid from Rust.co.uk but as Dr Wong says you do need the steel clean I had to redo part of one of my corners as the epoxy lifted from a small rust flake so I stripped at all back on that corner just to be sure and all was fine. That was last summer and all still ok when I checked recently.

 

[Matt Barnes]

thank you @Althulas and @DrWong ..cracking advice...I'm not giving up on the Lechlar yet.. I will give the deox another go.. I still need to get the front wheels off the ground and get the arch liners off so I can inspect the front end of the sills, so the grinding isn't over yet...I've got to take the zinc spray off to repair the holes I have, so it's only there while I'm doing the rear suspension. Once the car is fully in the air I'll give the sills the beans !

as an aside, what did you gents use for the underside ?.. i.e. where the tank goes; suspension, wheel arches ?

 

[DrWong]

I’ve done sills, bits of wheel arch, front suspension bits (ARB and brackets) and used the same workflow on all - poly discs > Deox > epoxy. That’s pretty much my standard approach now.

Give the Deox another go. The key is persistence. I know how mind-numbing and tedious it is to keep messing with the gel every couple days, wire-brushing and then re-applying it, but you just have to grit your teeth and power through.

 

[Matt Barnes]

I’ve done sills, bits of wheel arch, front suspension bits (ARB and brackets) and used the same workflow on all - poly discs > Deox > epoxy. That’s pretty much my standard approach now.

Give the Deox another go. The key is persistence. I know how mind-numbing and tedious it is to keep messing with the gel every couple days, wire-brushing and then re-applying it, but you just have to grit your teeth and power through.

thanks mate.... I'm going to give the whole underside a thorough clean, treat any rusty areas as needed, then was going paint some form of epoxy or stone chip and then paint of it with body colour....

 

[Althulas]

After getting to clean steel I would go over my surfaces with Phoskleen B which is an acid with phosphates that turn the bright steel grey and gives some protection you can read the gumf on the Rust.co.uk site. I did you zinc primer and then painted over with epoxy paint then added a layer of tiger seal as I have no compressor to use the 3M under seal which you can get in the appropriate green but in my case a rattle can to finished off.

 

[Matt Barnes]

After getting to clean steel I would go over my surfaces with Phoskleen B which is an acid with phosphates that turn the bright steel grey and gives some protection you can read the gumf on the Rust.co.uk site. I did you zinc primer and then painted over with epoxy paint then added a layer of tiger seal as I have no compressor to use the 3M under seal which you can get in the appropriate green but in my case a rattle can to finished off.

cheers.... I was thinking of some form of epoxy paint to "line" the underside with. I always thought tiger seal was in a tube, bit like silicon sealant?.. can you brush it on then ?... I have the correct top coat....Ta

 

[Althulas]

Yes you can, it’s sticky stuff to work with I had mixed results using a damp roller and a cut down brush to stipple the seal to try and get near a oem finish.