Paint confusion

Post by **ndevans** » Tue Mar 04, 2008 11:35 am

I'm a bit confused about paint types.

Can someone tell me what types of paint will & won't react together? i.e. acrylic, cellulose, 2K etc.

I put some grey acrylic primer on my grille, then some cellulose snowberry white topcoat & they reacted badly

. I have just bought some more acrylic primer from a different manufacturer (cellulose primer is apparently unavailable thanks to the H & S pansies in the EU). It say's suitable for use with acrylic & cellulose paints, but the shopkeeper thought that meant it's ok to put the primer on top of celly but not celly on the primer. I tried a small patch of the acrylic primer then a bit of celly snowberry white on top & it doesn't seem to react!!

Can anyone enlighten me on what goes with what, which primers to use etc?

Thanks.
Neil (AKA Confused of Bristol)

Post by **alex_holden** » Tue Mar 04, 2008 11:43 am

I think you can still get it. Search for "cellulose primer" on eBay.

Post by **chickenjohn** » Tue Mar 04, 2008 11:46 am

How long did you leave the primer to dry? It sounds like the solvents in the cellulose reacted with the acrylic primer, re-activating it and causing it to pickle.

Use an etch primer first, then try after letting the acrylic primer dry thoroughly a dust coat or two of cellulose top coat, when this is dry, then try your luck with a full wet coat of cellulose top coat.

Other than that, celly primers are still available from paint factors, but only celly primer in a can (i.e to be used with thinners from s spray gun).

Post by **ndevans** » Tue Mar 04, 2008 11:48 am

chickenjohn wrote:How long did you leave the primer to dry?

Pretty sure I left it for a day.

Post by **Orkney** » Tue Mar 04, 2008 11:50 am

Vipers nest Neil that is

think half of it is knowing whats actually on there.
Been looking at scab lately thinking of paint and reckon there are so many coats of allsorts the only way to go is back to bare metal

be just as well anyway as the brush paint jobs have accumulated somewhat.
I love it when i find a bit where the brushed stuff comes off golfball size revealing the original paint where some daft sod obviously never removed the polish before setting too with a brush.

Post by **Orkney** » Tue Mar 04, 2008 11:56 am

What CJ jut said - I'm pretty sure i can get celly primer in a rattly can here if of any use, going in there tomorrow so will find out for sure.

Post by **ndevans** » Tue Mar 04, 2008 12:06 pm

Thing is-what goes with what?

Is celly on top of acrylic ok? Is acrylic on top of celly ok? Where does 2K come into it?

All these things are a mystery to me, & shops don't really seem to know either, I guess they don't want to be the ones who reccomend something which then doesn't work.

Pretty sure I've got celly topcoat on the car, but the wings, bumper & grille are stripped down & need primer putting on.

Post by **Orkney** » Tue Mar 04, 2008 12:11 pm

from here on goog
http://www.scottpaints.co.uk/automotivepaints.htm

Paint Lifting Off in Cellulose when Painted Over Other Products: Lifting can happen when painting with cellulose over air drying enamel, because the top coat solvents are too strong. This can be avoided by applying a first coat of special sealer, which acts as a barrier.

Post by **jonathon** » Tue Mar 04, 2008 12:46 pm

The problem is with the acrylic paint which is really only compatible with similar products. 2K is a different type of product as is celly.
Its perfectly possible to 2K prime or even top coat onto celly. you can 2k prime onto celly then celly top coat too.
However try not to mix the types of paint and be very wary using etch on celly where you may have flatted through it as this can react either at the time of etching or when you apply a primer of any sort or top coat.
The main problem here is knowing what paint is on your car, and the quality of it. there are makes of paints that we would never use as they are just asking for trouble somewhere down the line.
Always allow plenty of time for drying, and you must ask the paintstore for a spec sheet and advice on different products and their suitability. If they are unable to offer this then walk away.

Post by **ndevans** » Tue Mar 04, 2008 1:04 pm

Thanks Jonathon. Pretty sure most of the existing paint is celly. So 2K primer is ok with celly topcoat-that's good, I have some celly to use up. Just need to get 2K primer.

cheers,
Neil

Post by **alex_holden** » Tue Mar 04, 2008 1:06 pm

ndevans wrote:Thanks Jonathon. Pretty sure most of the existing paint is celly. So 2K primer is ok with celly topcoat-that's good, I have some celly to use up. Just need to get 2K primer.

I wouldn't consider spraying 2K myself without a proper spraybooth and air-fed mask - nasty stuff.

Post by **ndevans** » Tue Mar 04, 2008 1:22 pm

So the H & S pansies have banned celly so that we can use something even more dangerous? That is madness.......

Post by **jonathon** » Tue Mar 04, 2008 1:24 pm

Yes, forgot to say that

If you have not broken through the existing celly top coat then just 800 flat and go straight on with a mist coat followed by around 4-5 wet coats,but allow at least 15 mins between coats (this applies to all paints)as the solvents need time to settle or evarorate.

3M do a cheap face mask which allows protection from 2K type paints, okay for you but not anyone else who might breath in the fumes, so beware.

Post by **Orkney** » Tue Mar 04, 2008 1:31 pm

He can paint & polish all he likes - wont change the fact he'll be returning south from here on the LEO sat on orange boxes when some unscrupulus person pinches his seats

J is there such a thing as a sealant undercoat that wont cause a reaction or are they type of top coat specific?

Post by **alex_holden** » Tue Mar 04, 2008 1:43 pm

ndevans wrote:So the H & S pansies have banned celly so that we can use something even more dangerous? That is madness.......

I think 2K is supposed to be being banned too isn't it? They want us to use a water-based pigment with lacquer over the top. If cellulose does eventually disappear entirely I would look into synthetic coach enamel instead (it can be either brushed or sprayed on - the main problem is that it dries very slowly so lots of time for dust and flies to land in it).

Post by **jonathon** » Tue Mar 04, 2008 1:44 pm

There certainly is Kevin, not ordered some for a while , but your paintstore will advise.

Post by **Orkney** » Tue Mar 04, 2008 1:58 pm

That'll be you shortly then

I'm a bit hesitant to go stripping the paint at the moment, tem and moisture not in my favour, simply cant wade in there and strip to bare metal and prime because from what i can gather primer is moisture absorbant so you need to be a bit quick sharp about it.

Now if there was an undercoat sealer rather than a primer that would stand for some time that would be the answer !

Post by **jonathon** » Tue Mar 04, 2008 5:11 pm

We generally use galve spray to preserve panels that lay bare for some time during rebuilds, but you need to check that the primer is compatible before you start proper paintwork. I'll check out a suitable 'barrier coat' for you tomorrow Kevin

Post by **ndevans** » Tue Mar 04, 2008 10:57 pm

jonathon wrote:you need to check that the primer is compatible before you start proper paintwork.

What we need is a chart cross-referencing what is compatible with what.

Post by **bigginger** » Tue Mar 04, 2008 11:02 pm

Would help if it updated regularly to keep in touch with things like a certain large car part supermarket's rattle cans of paint becoming incompatible with their primer

Hoping that was a short term thing/error on their part - gonna need to do some more paintin' soon
a