Under body treatment advice

[saracen]

Hi everyone
Fairly new on the forum. I recently started restoring a 325i touring. The car was parked in a barn for a good few years.
I stripped off everything underneath from fuel/brake pipes, fuel tank to front and rear axle with an intention to freshen it up and change all the rubbers and balljoints.
After getting the dirt off, the floor came out to be quite clean in my opinion. However, there are some rust patches that requires attention but generally the original underseal is still intact.
The dilemma I am in now - is how to treat the under floor and wheel arches. I prefer the look of original blue underseal thus reluctant to use schutz on top. I am not if clear waxoyle is any good as it wears quite quick.
Any suggestion would be helpful.
Also, What to use for the suspension parts. I am more inclined towards POR15 but I have heard the best result is on bare metal. Is that true?
Some photos are attached -not the best quality though but hopefully you guys will get an idea.
Thanks

[Brianmoooore]

DO NOT, under any circumstances, use schutz on any 'proper' restoration.
This stuff is intended to disguise bodged body repairs to extend the life of old bangers for a few extra years. The problem is that after a few years, this stuff hardens and starts to lift. Water gets under it, and at that point, the vehicles fate is sealed - a couple more years, and it dissolves into orange dust.
The existing underseal is polyurethane, and where it is still good will be absolutely fine. Just make sure you cut it back to eliminate every trace of rust that has crept under it, and replace the resulting bare patches with the real stuff, which can be obtained from 3M. For patching very small areas, I've used polyurethane adhesive/sealant from a tube, which can be 'finished' with a small brush dipped in white spirit.

[saracen]

DO NOT, under any circumstances, use schutz on any 'proper' restoration.
This stuff is intended to disguise bodged body repairs to extend the life of old bangers for a few extra years. The problem is that after a few years, this stuff hardens and starts to lift. Water gets under it, and at that point, the vehicles fate is sealed - a couple more years, and it dissolves into orange dust.
The existing underseal is polyurethane, and where it is still good will be absolutely fine. Just make sure you cut it back to eliminate every trace of rust that has crept under it, and replace the resulting bare patches with the real stuff, which can be obtained from 3M. For patching very small areas, I've used polyurethane adhesive/sealant from a tube, which can be 'finished' with a small brush dipped in white spirit.

Hi,
Thanks for your advice. I never knew about polyurethane.
What would you suggest to paint the suspension parts with? I do not want to strip off the original paint but do another protective coat on top. I was more inclined towards POR15 but I have read that they are not effective over paint.

[darkchild]

This is the brush on underseal.

http://www2.metalflake.co.uk/product_de ... id=3M08537

[Sanchez]

Wow, first touring I've seen with a aluminium arm, they all came with aluminium as standard irrc.

[Brianmoooore]

This is the brush on underseal.

http://www2.metalflake.co.uk/product_de ... id=3M08537

That's seam sealer, rather than underseal, which needs to be used as well, of course.
This is the correct underseal: https://www.spraygunsdirect.co.uk/prepa ... GKtU1.dpbs and, yes, it isn't cheap.

[Brianmoooore]

Wow, first touring I've seen with a aluminium arm, they all came with aluminium as standard irrc.

Just the one, by the look of things, unfortunately.
One of mine still has a matching pair in good order.

[saracen]

Wow, first touring I've seen with a aluminium arm, they all came with aluminium as standard irrc.

Just the one, by the look of things, unfortunately.
One of mine still has a matching pair in good order.

You cant change the ball joints on aluminium arms or can you?

[jimmyspeed]

If you just want to over paint and have a spray gun i'd get some lechler epoxy primer its a two part but not dangerous (still need mask)

Sticks really well, has rust inhibitors and is not porous like standard primers - then black it up.

[Sanchez]

Wow, first touring I've seen with a aluminium arm, they all came with aluminium as standard irrc.

Just the one, by the look of things, unfortunately.
One of mine still has a matching pair in good order.

You cant change the ball joints on aluminium arms or can you?

Supposedly no, But the question is how did they get in there in the first place?

[bigbird76]

POR 15 is crap if you dont get the surfaces blasted so i would stay clear of that stuff, Epoxy primer is the stuff to get, I used the Jotun stuff 2 part like jimmyspeed mentioned for my body and then used 3M stonegard which is great stuff.

Goodluck

Leigh

[saracen]

This is the brush on underseal.

http://www2.metalflake.co.uk/product_de ... id=3M08537

That's seam sealer, rather than underseal, which needs to be used as well, of course.
This is the correct underseal: https://www.spraygunsdirect.co.uk/prepa ... GKtU1.dpbs and, yes, it isn't cheap.

Im going to apply the 3M sealer only at the places that require attention. However, I also want to apply a layer of protection on top of origional underseal. I was thinking about clear waxoyl or is there any other product thats clear.
I have read that the clear waxoyl has a yellowish tone to it but still better then hiding the origional seal.

[biffer]

Bilt Hamber Dynax UC is similar stuff to traditional Waxoyl,but is supposed to be so much better. It drys clear too.

[jimmyspeed]

^ ditto - don't use hammerite waxoyl its crap for exposed areas. I was given an old tin and coated a wheel arch with it, it lasted about a week.

bilt hamber, dintrol, or tectyl 506 - which is what i used (not clear), infinitely better. If your doing a large area the tins are good, as you can brush over several coats and be sure its all well covered.

[saracen]

^ ditto - don't use hammerite waxoyl its crap for exposed areas. I was given an old tin and coated a wheel arch with it, it lasted about a week.

bilt hamber, dintrol, or tectyl 506 - which is what i used (not clear), infinitely better. If your doing a large area the tins are good, as you can brush over several coats and be sure its all well covered.

What do you guys think about https://www.dinitroldirect.com/product/ ... wax-1-ltr/
They sell complete kits as well which is more ecnomical https://www.dinitroldirect.com/product/ ... ofing-kit/ but I dont know why I have this stigma of not putting black or any other colour.
The other thing, do I have to get a compressor to spray it or can I just apply it with the brush? and how many of them would be sufficeient?
Cheers

[bigbird76]

Bilt hamber is what i used mate, I aslo used bilt hamber cavity wax. Dinitrol is also not bad stuff.

[saracen]

Just an update. This is where I have reached so far. Haven't been able to do the underseal yet. Would need some assistance with that.

[tiw30]

Any body know of a product I could use to recoat small areas where the original sealant has came off and rust has started, just surface rust and cleans up well. I will prime it but would need to cat it in something like 3M seam sealer of other type of suitable sealant, I don't have any spraying facilities so it would need to be brushable or available in an aerosol

Thanks in anticipation
Glenn

[Brianmoooore]

For patching very small areas, I've used polyurethane adhesive/sealant from a tube, which can be 'finished' with a small brush dipped in white spirit.

[tiw30]

Thanks Brian, I will pick up a tube of 3M sealant and spread some neatly over the areas affected

[BristolE30]

For patching very small areas, I've used polyurethane adhesive/sealant from a tube, which can be 'finished' with a small brush dipped in white spirit.

What product would you use?