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advice on spraying cellulose please

Posted: Wed Jul 22, 2009 4:30 pm
by Suede Ed
My GP project is at the painting stage, its all blasted back to bare metal and i have etch primed the panel work with Upol Acid 8, I have decided to go the cellulose route as i'm doing the job in my garage; i have sprayed some of the parts with cellulose primer and the results dont seem too bad so far apart from fibres coming off tack rags :? I have flatted the primer back after this and put on another coat, I have a few questions if anyone can help;

How many coats of primer? How many coats of colour? Should I flat after each coat of colour and how much should i thin the paint? 50/50?

Any other paint advice would be welcome,

Cheers Gents

Re: advice on spraying cellulose please

Posted: Wed Jul 22, 2009 10:13 pm
by joespeed
the more coats the better and well flatted between coats,
i find that the prep.work of all paints this is the worst/hardest and less forgiving but easier to sort out mistakes and it is not such a health risk!
practice makes perfect,
regards
joe

Re: advice on spraying cellulose please

Posted: Thu Jul 23, 2009 1:12 pm
by Monty
Undercoat all depends on the quality of the original parts, Its bound to have a few dings or at the very least a few rust pits that need filling. They are the things that stand out when its all finished.
I give one good undercoat in say grey and then a light coat in say red lead, An aerosol is fine, then a good coat in grey again, then a waft over with another dark colour, black or navy blue (again an aerosol is fine) Start to flat it back with 400 and stop when you hit the red, (the water will start to go pink) at that point you still have one good coat of grey and you are then looking at areas that still have the black, these are the low spots, and may need another coat of grey to build it up, If you have any high spots a tap with a hammer works great, it can work for the low spots if you can get at the other side. Take care on edges as you can cut through to bare metal easily.
when you can rub over the whole panel and not have any of the black showing, its time for top coat, if you are not planning on metallic, pearl colours you don't need to lacquer, 5 or 6 light coats is better than 2 heavy ones, flat each coat and use more good quality thinners on the last few coats, flat the last coat and buff with a polishing wheel and G3 cutting compound.
After doing mine through the winter my only problem was the damp and trying to get the garage warm. Very important when you are throwing water around when flatting down. Yes its better to spray in a separate room but needs must.
Go for it, runs can always be rubbed out, in fact if you get one, let it gel up and give it another coat, then let it dry well before rubbing it out with 400 again, go down to at least 1200.
Worked for me.

Re: advice on spraying cellulose please

Posted: Thu Jul 23, 2009 9:19 pm
by J1MS
Old tech sheet that I was given many years ago...(and I might still have it somewhere) says One single header cross coat followed by two double header cross coats, leave approx 20 minutes between coats or until the paint is just going off tacky, as the paint works better on a not fully dry coat below the next coat.... The Celulose paint notes I had were from an old Burgess paint shop(1978) and were given to me with the paint... Thinning was done with the use of a viscosity cup (and the paint when correctly thinned) a set amount ran through the viscosity cup in a set time... ml/sec...

Re: advice on spraying cellulose please

Posted: Fri Jul 24, 2009 11:06 am
by Suede Ed
See thats the thing J1, I've heard of so many different methods such as 'let it dry for a day between coats then flat' and as you have said 'spray a coat let it flash off for 20 mins then put another coat on' , i tried this when spraying wheel rims with rattle cans and it worked well. I think I'll try a few different methods on the back of panels etc, to see which is best. Another question; Gonna spray it red, which off the shelf paint matches closest to original GP red?

thanks again for the input

Re: advice on spraying cellulose please

Posted: Sun Jul 26, 2009 7:20 am
by lammydave
Suede Ed wrote:. Another question; Gonna spray it red, which off the shelf paint matches closest to original GP red?
ford radiant red??

Image

Re: advice on spraying cellulose please

Posted: Sun Jul 26, 2009 5:31 pm
by Suede Ed
Spot on Dave, if mine comes out as good as that i'll be well chuffed!

Re: advice on spraying cellulose please

Posted: Tue Aug 04, 2009 9:20 pm
by Andy
Ref the top coats, you dont flat between coats.With cellulose theres certainly an art to it but its generally thinned down more as further coats go on. Leave for around ten minutes between coats, around 4 coats is sufficient to allow for cutting back with the last coat applied 'wet' but obviously avoiding runs. My Tv1 was painted this way.

Re: advice on spraying cellulose please

Posted: Tue Aug 04, 2009 11:25 pm
by J1MS
Andy wrote:Ref the top coats, you dont flat between coats.With cellulose theres certainly an art to it but its generally thinned down more as further coats go on. Leave for around ten minutes between coats, around 4 coats is sufficient to allow for cutting back with the last coat applied 'wet' but obviously avoiding runs. My Tv1 was painted this way.
Have seen paint thinned at up to 70% thinners for a last coat using quality top coat thinners... Paint was like glass smooth and very shiny

Re: advice on spraying cellulose please

Posted: Wed Aug 05, 2009 8:38 pm
by lamblast
i never flat between colour coats you can sort any nibs or runs at the end by flatting and compounding i tend to leave it a week before flatting and compounding as the paint is still drying