underside factory finish

[Peet]

before i start building my shell up i am going to underseal all under the car to help protect it a bit.

does anyone know if they left BMW body coloured on the underside or if they left in black under seal.

[bss325i]

Neither.

They were beige polyurethane undersealed with body colour in the wheel arches or matt black in the wheel arches on lighter colour cars like red and white with some body colour overspray on parts of the underside.

[Fastroad]

Exactly as BSS325i said, beige with some body colour overspray

[Peet]

reeto, thanks for the info,

was just wondering cause the other e30's i've had where all black with what i thought was overspray (both had been resprayed) but this one is red all over (apart from the odd patch of black on the hidden areas - under the fuel tank and round the rear valance / wheel well)

will source some underseal and get it done before it gets the chance to rust

[polsta]

Make sure you get the right polyurethane stuff and do it properly

[Brianmoooore]

Black underside on an E30 usually means one to avoid. It's likely to be shultz based shite sitting on rust.

[Peet]

will have a look into some stuff, think the dynax stuff gets good reviews.

makes sense to do it right with it being so clean

[Brianmoooore]

Make sure you get the right polyurethane stuff and do it properly

[Peet]

Black underside on an E30 usually means one to avoid. It's likely to be shultz based shite sitting on rust.

haha yeah i'd agree wi that going off the other 2 i had

the one i have now has lived in a class room since it left the showroom

[Ianb]

I was going to ask exactly the same question. Some time back i bought an immaculate lapis blue 316 non sunroof cromie auto and I've just got round to stripping it and the whole underside ie floors / inner arches etc are all properly painted lapis blue! I thought this was strange but it's definately original underseal, not a single weld on the car and all i've found now that it's gutted is a 1 inch by 1 inch area of rust that was behind the fuel filler neck on the rear inner arch caused by trapped mud. Aside from this the paint under the arches, on inner wings etc is in good condition. It's caused me a pain in the arse actually because where i would have just checked for rot I've now had to nylon brush under each arch, then Gunk it then Steam clean it - I keep saying to myself just leave it but once you see the shiney paint as opposed to the usual rust it becomes an obsession

[polsta]

dont forgetpeople can have it painted, thing is with these cars at the age they are, theres a lot of rust lurkking under that nice looking underseal even if its unbroken, light surface rust etc, that if not caught will develop in to holes and you wont know until it causes issues, its very good practice to take it all back and rust hunt and re do it

to give you an idea heres mine, 1986 tech 1, original color wasnt black or beige ? looked more like body color on the inners

start


to this





to this









very happy with the results and being garage kept and no winter use will be good for many years to come

[Ianb]

I know exactly what you're saying Polsta, I am as sure as i can be that i have no other rust. It is strange though as I can't see anyone respraying the underside of a poverty spec 316 auto, as thouroughly as this one has been and all the parts I've taken off have no overspray or anything and have not been refurbed before. I think havng 14in BBS and 4x4 esque ride height combined with a weedy 1.6 auto means there's far less sandblasting been done on the underside / inner arches. There's no chance of me putting it on the road anytime soon either as enthusiasm has taken a dive lately and I've also been hit with the morbid realisation that a dark blue e30 with fixed rear Qtr lights no sunroof, no aircon and wind up windows will be like a bloody oven in summer and i wasn't planning to use it in the winter!

[polsta]

it should be fine in the summer, rear pop out windows can be got for around £60 a pair from traders on here post a wanted ad

i have no idea about your underside being blue if original or not, sounds like a nice shell/car, as its an old car it is possible it was refurbed even 10-15 years ago and done properly hence the parts loooking old still and no overspray, who knows ? get some pics up would be good to see

[G-Bear]

I have similar planned tasks ahead.

For underseal, I was going to look into this stuff.


http://catalogue.3m.eu/en_eu/eu-aad/Sealers


I think I'll go for the sprayable sealer over the brushable (assuming they're the same product) mostly for aesthetics. To be honest I haven't researched it much yet, but am assuming this isn't the notorious bitumen based stuff? Like I said, I would probably call 3M for more details before ordering..

[bss325i]

to give you an idea heres mine, 1986 tech 1, original color wasnt black or beige ? looked more like body color on the inners

Neither.

They were beige polyurethane undersealed with body colour in the wheel arches or matt black in the wheel arches on lighter colour cars like red and white with some body colour overspray on parts of the underside.

It's the floor pans and such like that is still beige.

If you drop your fuel tank down you will see clean beige sealer.