The Spray Painting Thread

[TurboRA28]

Ok I attacked the guttering with a wire brush on my drill and got the rain damaged por15 all out..
So can start from scratch again.

This is all really doing my head in and am realising how out of my league I currently am.. The por15 guys are getting sick of me I think so I am hoping to ask a few questions on here for those who have had experience.

So basically the deal is this..

The Coaster roof had some decent rust in guttering and seams which i've cut most out and welded in new metal. Other areas a good clean up and treated with the marine clean then metal ready by por15.

So thats where I am at now..

Now my plan was to paint all rusty areas with por15 along seams and guttering and few other patches and over my repairs. Put new sealer in the seams and guttering. Bog over some dinted and repaired areas. Not necesarily in that order.

I then have purchased some 'barrier shield' paint which is to help reduce heat. It is a rough textured finish. I want to paint the whole roof in this. It has a good rep and works as a bit of a rust protect and leak fixer also. It comes in a 3 stage process, a primer, the sheild, and a top coat.

I am totally confused about the order of events.

1. Clean whole roof with marine clean and wash off
2. Apply metal ready to all bare metal areas and rust areas and was off
3. Por15 on bare metal and rusted areas and seams and guttering
4. 3 hours later 2nd coat of por15
5. 3 hours later dust coat barrier sheild primer over all por15 areas
6. Bog over repairs
6. Sand bog when hard
7. Another coat of por15 over bog
8. Prime whole roof with barrier sheild primer
9. Sikaflex seams and guttering
10. Barrier sheild coat
11. Barrier sheild top coat

Do I have to move anything around here? My main unsure areas are the dust coat of primer and bog.. I thought I read somewhere that the por15 needs to be tacky to apply the bog. So not sure how to manage that and incorporate the dust coat. Also unsure when in the process to apply the sikaflex seam sealer.

If I do everything in the correct timeframe and order it would seem no need for por15 tie-coat?

Thanks
Joel

[o_man_ra23]

I would put the seam sealer under the primer. Also would not bother dust coating, just give the POR15 a sand prior to priming (allow it to dry overnight) and this should key plenty well enough.

[TurboRA28]

My main reason for wanting to dust coat and not sand is that some of the areas are near impossible to sand.. eg. this time to remove it I had to use a metal wirebrush wheel on the drill..

["Z" UTE]

Joel, in my most humble of opinions, you are using more than 1 product that does the same thing, and it is certainly causing you some serious grief.

Basic steps:

1. Remove rusty parts and replace with fresh metal,

2, Treat any surface corrosion by mechanical grinding scouring, then use a phosphate coating. POR15 will contain a phosphating agent, your 3 stage camper roof system will also contain a similar substance.

3. Prime, bog and shape, prime again, seam seal, then

4. Top coat.

Yeah sure POR15, and your other proprietry camper roof paints maybe good stuff, but I would use one or the other, not both.

cheers Chuck.

[TurboRA28]

Thanks Chuck, it does seem i'm getting in a mess with two products. The reasoning was Por15 has such a good reputation for rusty stuff and the coaster roof is definately rusty.

So i've dug out all my shite and the campervan stuff.. So they provided a product called Penetrol to be used as the primer, followed by the barrier shield and then top coat.

So are we thinking I should totally remove any por15 and use penetrol/barrier shield process?

I did read though that bog and penetrol don't mix well?

[TurboRA28]

The other option, is could i por15 and tiecoat the whole roof, and then put the barrier sheild directly over the tiecoat? Completely eliminating the penetrol?

["Z" UTE]

Joel, if bog and Penetrol do not mix, dispense with the Penetrol. The name Penetrol is something I am familiar with as a penetrating lubricant used by the US armed forces.

My current thoughts are that the "Barrier Shield" would normally be applied over a roof which has a somewhat intact topcoat.

cheers Chuck.

[TurboRA28]

Yeah I am really hoping it will go over the por15 and tie coat primer.. I'm unsure why they market it with a primer like penetrol.

[1JZ-Rolla]

I finally got around to pulling some panels from my car for a freshen up, and found the beauty of soda-blasting, i'll never pick up a paint scraper again!

The finish hasn't even seemed to harm the factory panel coating. So my question is, how should I prep it for primer? Just a light sand with 180 grit for adhesion?




Cheers
Phil

["Z" UTE]

320 grade paper Phil, the rougher papers are for bulk removal of paint and shapeing filler.

Spray a light coat of etch primer, (I have 20 litres if you need a few grams) then a coat or two of primer. A light guide coat of black, (pressure pack can will do) sand with 320 on a long board. This will show you any low spots, or high spots. Tickle the spots with a hammer and dolly, and use your 320 on a block to guage how well you have done. You may need a light skim of bog, Jeffro can supply the good microfine PPG filler. Re prime and guide coat the repair areas sand again with 320. Give the whole panel another coat of primer, and when that has flashed off spray your colour coats. With the paint you are using, 2 coats should be sufficient, as the 3rd will start to build orange peel.

cheers Chuck.

[1JZ-Rolla]

Geez chuck, sounds like you are assuming i'm a patient person? haha. I can see me skipping about 3 of those steps and finding something mechanical to do instead

Will definitely take you up on the offer of a small amount of etch primer though please, with suitable compensation of course, since it saves me buying litres of the stuff.

I'll hope to get good paint transfer and even coverage to only have to stick to 2 top coats of colour, cheers.

[JZA70R_92]

did you use some sort of diy soda blasting kit?

[1JZ-Rolla]

nope, paid a professional

["Z" UTE]

did you use some sort of diy soda blasting kit?

If you are looking at home soda blasting, make sure you buy a "Soda Blasting" setup and not a "sand" or shot unit. The nozzle and feed valve orrifices are soooo much different.

You can buy the "soda" cheap at swimming pool supplies shops, Soda Ash. Or you could buy eleventy trillion boxes of baking soda.


cheers Chuck.

[o_man_ra23]

Is it just a matter of sanding the surface to allow paint adhesion?? If so, this would be a good way of blasting panels such as guards and bonnets where you can get at 99% of the inside of the panel.