Spraying Advice

[Liam1805]

Need some help with spraying guys, right scenario is i have sanded down my bay with 120 grit to give it a nice key, where i have surface rust is now back to bare metal but still have some pitted areas in the bare metal, this is what i want to know

1 - Do i treat the bare metal with a rust treatment or will zinc primer do the job of stopping rust seeking back through ??

2 - When it comes to primer shall i filler primer then normal primer on top ??

3 - What grit should i sand down in between coats and should it be sanded between every coat ??

[envoy cdx]

Use something that will prevent the rust reoccuring, a bit of zinc primer won't hurt either, as for the primer, if there is pitting then a filler primer may hide these imperfections, depends on how bad they are? Maybe worth putting a dab of chemical metal over and flatting that back to shape?

Pics would certainly be better than trying to imagine your situation

If your painting wet on wet (10-15 mins between coats) then you won't need to sand (or be able to for that matter).

[Liam1805]

Ok no worries i shall treat the bare metal first then zinc primer over that. Will the zinc primer need to be sanded also though, then i will give it some filler primer over the pitted areas which aint that bad, then i will normal primer it does that sound ok ??

[the tattoo stud]

um, why primer over the primer? are you useing 2k filler prime or some celly? if your useing 2k, its basicly like spray on ispon any way, so flatting it smooth is a joy, and ive only ever used filler primer then colour, never felt the need to prime over prime....you can also add a little of the colour to the filler primer so you have a more even base for the top coat.

[Liam1805]

I will be spraying with can, reason i was going to primer over the filler primer was due to the colour of the filler primer, unsure weather it would affect the top colour in any way. Any ideas what grit paper i should sand down with in between coats and how long would you leave each coat to dry

[richie00boy]

Put your zinc primer on then the high build, no need to flat between unless you mess it up a bit. Then flat your high build if you feel like it and put your colour on. You only reallty need to flat between coats if you leave it longer than about 8 hours.

Don't expect can high build to be vastly different from normal primer, it takes a lot of coats to build. TBH unless you are building a super smooth show bay I don't think you would notice any difference just going straight on with colour on top of zinc primer.

[Liam1805]

Thank you for that input Richie, if the coat has gone past 8 hours what grit should i flat it with, also how long after one coat should it be already to put another on top ??

So plan is rust treatment on the bare metal areas, then zinc primer over the treatment and then top coat yeh ??

[the tattoo stud]

carefull with that crap out of a can, make sure its not an incompatible paint to your top coat...I bought some rubbish from Halfrauds, took an age to dry, and then the celly I had reacted and i had to bare metal it from scrath.

600 then 800 between coats, 1200 then 2000 for finnish.

[Liam1805]

Well all the paints i will be using are from halfords so they should be compatable

[Liam1805]

I have now painted on Kurust treatment on the bare metal areas which have now turned a nice purple colour, does this treatment need any sanding or can i just carry on with the zinc primer over it ??

[the-darkhorse]

u dont sand kurust , u wipe/brush it on leave for 15 - 20 mins then u wipe it on again and wipe off straight away ,
as a hint on the back off the tin there is some instructions too lol ,, good luck using halfords quality products

[Liam1805]

u dont sand kurust , u wipe/brush it on leave for 15 - 20 mins then u wipe it on again and wipe off straight away ,
as a hint on the back off the tin there is some instructions too lol ,, good luck using halfords quality products

Haa i know that, but if i wipe off there wont be any on there, so i just leave it as it is now and go ahead with zinc primer yeh, whats problem using halfords paints mate

[the-darkhorse]

the kurust aint meantt to stay on it will eat into the paint , im a professional painter and using stuff from halfords is rarely done as there paints are very poor in my opinion ,

[Liam1805]

So there no need to use kurust at all then in other words, i thought it acts as a protective coating to prevent further rust, only engine bay im doing so does not need to be perfect really

[the-darkhorse]

you use kurust to kill rust or hold it up to speak once you get rust if your just after procedure to paint a car it would be in my opinion again ,
etch primer....... primer ....... base colour.......... clearcoat ( modern style ) 2005 onwards
etch primer .......primer ........ solid colour ( old style ) pre 2005
this is a guide as some manufactors chose to change earlier or later hope this helps

[the-darkhorse]

etch primer and zinc primer are diffrent products , etch is the process i would use , can be bought most bona fide paint suppliers i guess halfords might even sell it lol . just try to get a good brand if poss

[Liam1805]

Thank you i appreciate that, when i mentioned i used kurust i forgot to mention it was on bare metal not the paintwork. When you say etch and zinc are different what difference would using zinc instead make

[the-darkhorse]

zinc is for putting on bare metal so you can weld through it , normally used in a panel shop before it progresses through to the paint shop fella iirc , if you have used zinc you must etch it then primer or you could have adhesion problems , i.e paint flaking off

[Liam1805]

zinc is for putting on bare metal so you can weld through it , normally used in a panel shop before it progresses through to the paint shop fella iirc , if you have used zinc you must etch it then primer or you could have adhesion problems , i.e paint flaking off

No worries personally would you leave the karust on the bare metal or remove it, in some areas of the bare metal i have pitting which i cant remove. So i need to go buy myself some etch primer then and just use that rather than the zinc

[Liam1805]

Leave kurust on bare metal patches then etch primer over it or remove the kurust and just etch primer the bare metal patches (bare in mind there are some pitted areas) need your input guys urgent so i can crack on

[richie00boy]

Right lets clear a few things up

Kurust is not designed to be wiped off, that's another product. So what you have done is fine.

You don't need to etch or otherwise prime over zinc primer. Some bodyshops do use it as a weld through primer, but most use it for it's rust preventative performance.

So just follow what I said in my previous post. As for the flatting between coats, P400 would be fine, but it's not critical - anything from P320 to P600 would do. Only very lightly do it and with wet paper, it's only to dull the surface not rub it away, and to take out any blobs or small imperfections.

Halfords paint is fine. Enjoy the project.

[the-darkhorse]

Mmmmmm. Wet flatting still? and would products in a can cover 600 wet flatted. ? Silly me spending money on spray guns and a water based paint system and a spray booth when halfords would do! !!!!! Wish i had spoke to you first richiooboy
shall relay this information to my customers when painting there cars.
why we bother at all when reading this has enlighten me to what some people is acceptable.
my bad i was thinking of genolite kurust which you wipe of after your final procedure.

[richie00boy]

Looks like somebody got out the bed on the wrong side today

Halfords cans are fine as far as cans go, in fact fine for odd DIY jobs. Spraying cars for a job of course I would use a gun - better, quicker and cheaper result. I don't think you need to spend out on a compressor setup just to paint an engine bay in one car.

[the-darkhorse]

Confess one grumpy professional painter eating humble pie.

[the tattoo stud]

whats problem using halfords paints

The problem is its utter crap. Its not even cellulose as you might have known it from back in the day, it doesn't flat properly, it doesn't polish or mop properly, any paint you put over the top of it, including 2 pack or even tetrosyl stonechip will react with it, it goes on pish thin, and i'm my opinion is worse than useless...you'd be better of going to B&Q and buying some non drip gloss and brush painting your car.

personally, I'd but a £40 gazebo from argos, £14 worth of 3m sheeting from any paint suppliers, a £15 crappy but professional spray gun, and hire a compressor for the weekend......anything less and your just wasteing your time, money, and motor vehicle.