How To Paint A Panel With Acrylic Paint?

[Peter]

Hi Guys,

So I want to have a shot at painting my door due to damage....so far I have:

1. Disassembled door and fixed all damage - panel beating, bogged, primed etc.

2. Sanded the rest of the door back to a matt finish using 800 grit wet and cleaned with wax and grease remover.

Now from googling I will have to:

3. mix 1/3 paint with 2/3 thinners and stir.

4. set air pressure to spray gun recommedation - I am using a gravity fed gun - high volume low pressure (HVLP).

5. Begin spraying from approximately 30cm distance with an overlapping motion (15cm fan, 1.8mm tip on gun).

6. Apply 6 - 8 coats of colour.

7. Allow to dry.

8. Sand with 1200 grit wet

9. Apply 3 coats of clear.

10. Allow to dry for 24+ hours.

11. Sand with 1500 grit wet.

12. Polish with a rubbing compund to gloss.

Can you please let me know if I have missed anything out or got anything wrong? Before taking it to a shop, I thought I would give it a go myself.

Thanks,

Pete

[aussietroy]

I did this with my front bar, acrylic doesnt go as shiny as 2pac and will never completely match, but really no paint job will ever completely match. Just make sure the prep work is done right, dont cut any corners or it will show later on. I have a rough spot on my front bar from where I got lazy with the prep work.

Edited January 19, 2012 by aussietroy

[Peter]

Thanks mate - will focus on getting the prep work done as best I can. Unfortunately I haven't managed to progress at all as it has been so humid in Perth recently, didn't want to risk painting and getting moisture in the mix.

Couple of questions I did think of though:

1. When I sanded it back, on the door it creases out slightly and this has gone down to metal (small hairline section - about 5 cm long and 1 - 2 mm wide, just where the crease is) - will this be a problem, or if I make sure this is surface rust free, can I just spray straight over it?

2. Suppose the second question is self explanatory - have I missed any steps out or got anything wron in my first post?

Thanks for your help,

Pete

[sky017]

hey

usually you will need to prime over bare metal other wise you will get so called 'fish eye' , usually goes sorta wrinkly around the bare metal if you dont prime properly . depending on what kind of quality your after i would recommend go to the paint shop and buy a product called barcode , which you spray over the primer to seal the metal and prevent it from getting that fish eye.

on the other side i wouldnt bother with acrylic , yeah its good for amatures etc . iv used it on a few cars over the past , and i have to say its okay for a temporary fix , but itll never give you the finish you want, and by that i mean durability. acrylic can produce an amazing top end shine which is supposed to be better then 2 pak but no one does it these days as it takes hours to cut it back through the grades and compound cutter etc , but i warn you all it takes is a few splashes of petrol when your filling your car up , and its ruined. i did the rear on my r34 a year ago and had it dribble down , and ruined my mirror finish.

if its a car your going to keep for years to come , just suck it up and find a good cheap spray painter , and get them to blend it in properly .

[BrisTroy]

Ok, so here's wat i've worked out so far. (excuse the obvious being pointed out, a mate of mine yesterday was sanding back a layer of paint from a front bar with the dry 60 grit sandpaper for timber) so i'll try be thorough.

As much as the damage "doesnt look too bad" with some shiny paint left intact in places, be brutal. Its gomna be fixed, so dont try and preserve anything. Always easier to do a bigger area than blend a repair.

I usually start with 220 grit (wet n dry for all this, paper or sander in one hand, bucket and sponge in the other) for taking back paint, but for removing old bog or fibreglass, might go down as far as 80.

Take off a few layers of paint and see what you're up against, bog always binds better to bare metal too.

You can obviously mix bog correctly, fill and shape, its the sort of thing you'll wanna let dry overnight to be sure its set, everything takes time.

Fill holes with "metal fill" its a cross between fibreglass and bog. Harder to sand than bog, but so much stronger.

Once overfilled (always over compensate the shape you want) start sanding back with either 220 or 600, depending on the area being done, 220 for something the sander is going to have a lot of movement over, 600 for finer areas and corners.

Hopefully by now you have the shape you want, if not, repeat bog step above, only using 600-800 this time, being more particular to fine ripples or dips.

"Spray Putty" in a can is a godsend. Its a spray on, fine layer bog ideal for getting rid of stone chips or scratches. Allow about 5 hours for a generous coat of this crap to dry though, it can also undo a lot of hard work by "peeling" the whole layer off if u sand with too much pressure before set overnight.

Sand with 800 now, focusing on imperfections, air bubbles (you see these when the job is dry, so its important at this stage to keep washing down with water n sponge, and rag drying) and overall job finish. Ask yourself, is this ready for topcoat? By now it'll be looking pretty alright, but mulitcoloured. Base coat prime 2-3 coats now, and allow a few hours to dry.

Now that its all 1 colour, you're probably cursing at those spots you didnt feel or see earlier, so again make friends with the spray putty and sander. Get it right at this stage, or no amoutt of polish at the end will get you out of the shit you end up with.

Once happy, give a final coat in surface primer, allow to dry for a couple of hours, and give a light sand back with 1200 to smooth over. You're practically polishing it here, not removing paint, so focus on removing any scratches, and dont stay on the one spot too long. Wash with water and a sponge, allow to air dry, then use "prepwash" or similar to wash off remaining paint dust.

Happy with how it looked buffing with that shiny liquid? No dents, good shape? Buff dry, and check for pinprick holes from air bubbles.

Topcoat time.

Any acrylic in a can will do, but autobarn can mix any auto colour to a paint code, usually no more than 30 bucks.

3 even coats, allow a few hours to dry, then 1200 it smooth, wash with sponge and water, prepwash and allow to dry.

Clear coat is this process repeated, but dont touch with paper once sprayed.

48-72 hours is time required to dry for clear to be cut back.

Start with 600 to remove orange peel look, then 1200 to remove the 600's scratches, then 3000 to remove the 1200's scratches.

Finally buff with a cutting compound, and finish with a polish/wax.

This was originally a PM, but good info to share here. Feel free to add anything i left out or go into more detail. Hope this helps.

[Peter]

Thanks for all replies guys. The thing is I have a tin of acrylic paint, premium thinners and the door sanded back and ready to go - so I'll give it crack and see how I go - if I stuff it up I'll sand it back and try again...and maybe again...if I fully fail then off to the shop - just trying to DIY to save some cash at the moment.

Any other advice is always welcome!

Cheers again!

[BrisTroy]

95% of a good paint job is the prepped surface underneath straight and smooth is wat ur aiming for

[Peter]

95% of a good paint job is the prepped surface underneath straight and smooth is wat ur aiming for

So I have used a primer filler on the door and sanded it back with 1200. A bit of the door needed more work than the rest, due to sratching, which has now finalised into a smooth finish...but the extra sanding has caused that section to be taken back to the old paint. There is no clear, just paint.

Can I begin spraying in acrylic and spray over this whole area, or do I need to re-prime this section again?

Thanks for your help!

Peter

[BrisTroy]

So I have used a primer filler on the door and sanded it back with 1200. A bit of the door needed more work than the rest, due to sratching, which has now finalised into a smooth finish...but the extra sanding has caused that section to be taken back to the old paint. There is no clear, just paint.

Can I begin spraying in acrylic and spray over this whole area, or do I need to re-prime this section again?

Thanks for your help!

Peter

Quick squirt with etch primer will do it. Start with a few VERY light coats to avoid fish scaling around the edges. This happens when the thinners in the new paint softens the edges and causes it to lift n bubble before the new paint dries. Wafer thin coats, with 10 mins dry time between should be sweet, good luck