Re-Spray and prep

[robp]

I've got a peeling issue with my rear bumper after it was knocked a few weeks ago, and am considering re spraying that, the bonnet - crazing around the badge, and lines starting to show through, and the tops of the headlamps as they have what looks like bubbles in the surface.
I have a compressor and a very fine spray gun for it, but am more concerned about the preparation process - what would people suggest? do i need many layers of undercoat given that i am going to stick with the same LRG? given my peeling, i expect to have to do some sanding at the rear end. is there anything else i need to worry about?

I'll post a few pics soon, and as i'm not going to get anything done this month, you can admire my flakiness at Hethel next month.

[theelanman]

Ive never painted the m100 so dont know but I have done some spray work on the old elan.......different paint technology might have meant a different application...however here goes.....

the 'primer' surface is actually a gel coat designed to seal the body...fibreglass absorbs water and can 'bubble' under the paint if it makes it past the gel coat layer.......
the idea on the old cars was not to break the gel layer....this would stop cracking and bubbling....I presume it'll be something similar on the new cars....so what I'm trying to say is that where you have cracks you need to take it bake to glass.....where you dont then you just nee to remove the top coat and key in.......especially if youre staying the same colour...

hope that makes sense

cheers
G

[muley]

Hi, I prepared my bumper by rubbing it down with a random orbital sander with 280 grit disks. Essentially I had to remove most of the paint, down to the grey undercoat/get coat. I found the cracks and peeling were virtually all in the paint layer(s)

It was then sprayed with a primer / filler which was rubbed down with wet 800 or so wet and dry (used wet). I used a local body shop to do all the spraying, so I'm not sure if the primer / filler stuff can be done at home.

Cheers

Jim

[robp]

thanks for the advice, I'm probably going to wait until the car is garaged up for the winter, then give it a go.

Cheers


Rob

[al]

hey rob, there's a write up on the Wiki that I did when I had to respray my bumper, maybe it'll be some help ...

Summer might be better from a temperature/moisture point of view, but I'm no paint expert by any means !

A.

[surfboardfiller]

Rear bumper doesn't have gel coat, its an impact resistant polymer.

Gel coat is used to get things out of moulds easily and give a smooth finish as the glass will leave a texture. Paint usually flakes off the soft bumper. An adhesion promoter can be used but a bumper primer should do it.

[bobbrown]

There are special primers for plastic bumpers and the paint needs to have a plasticizer added other wise the paint will crack when the bumper flexes.


Bob

[robp]

Al, just read through your wiki - it's great, thanks. dotn suppose you happen to have the paint code for LRG?

thanks

[al]

Al, just read through your wiki - it's great, thanks. dotn suppose you happen to have the paint code for LRG?

There are several

If the paint code isn't on the VIN plate in your engine bay (only some cars have it - mine didn't) phone up Lotus with your VIN and they'll tell you what the paint code for your car's original colour is.

[GeoffSmith]

Lotus Racing Green should be B21 (A082B6304F) - see the Wiki!

[bobbrown]

Colour match is not totally down to the paint code as there are differences between paint manufacturers.
Also the prep has a lot to do with colour match, for example if you use a dark primer on blues the blue will come out dark, blue is usually applied over a white primer.
I do not know the requirements for other colours but it is some thing you need to be aware of, most good sprayers should know this.

[al]

Colour match is not totally down to the paint code as there are differences between paint manufacturers.
Also the prep has a lot to do with colour match, for example if you use a dark primer on blues the blue will come out dark, blue is usually applied over a white primer.
I do not know the requirements for other colours but it is some thing you need to be aware of, most good sprayers should know this.

The wiki write up mentions this to some degree, at least testing the difference between light and dark primers. Also we're talking about a 15 year old paint job, the likelihood is that the new paint isn't going to be exactly the same colour as the old paint anyway due to fading if nothing else, but it helps to at least start from as close as possible.

For Elan colours there are two lots of paint codes depending on colour and year, A?? codes relate to ICI colour codes, and B?? codes are Dupont's, several general colours ("racing green" for example) have multiple paint codes (I seem to remember being told there are 4 for racing green) and so the best bet is to call the friendly helpful people at Lotus with the VIN.

[bobbrown]

Fully agree with the original paint faiding over time, there is also the issue of paint of the same code but from different batches being slightly differnet it can be very tricky to get it just right.
I know I've been there and got the scars