The Spray Painting Thread

[TurboRA28]

So im coming close to cutting out and welding new metal into the Coaster bus.. I'd say there is more new metal than old now! Not quite but close

Anyway.. I have come to the conclusion that I am shit at bogging. It's going to look like a POS if I try and bog over the repairs.

Reckon i'd have any luck finding a panel beater or even apprentice who would want some cash in hand work on weekend to bog/sand my repairs ready for me to prime and paint?

[1JZ-Rolla]

Thanks Chuck. Fortunately i'm not using the Spartan high fill primer as my final prime coat, will be sanding it down considerably so the orange peel doesn't concern me too much, more just annoyed at the whole fault diagnosis process doing my head in while shooting the paint

I feel your pain Joel... bog is not my friend either.

["Z" UTE]

Phil, if you need a hand with the bog, give me a yell, 'tis like icing a cake for me.

Joel, most common mistake is mixing too much bog and trying to do too large an area at one time. The plastic applicators are good, but a stainless steel spatula also works well. I have four different sized spatulas/scrapers in the bog kit. Skim coating is the only real time you mix a heap of bog. For heavy applications, consider using the fibreglass filled bog.

cheers Chuck.

[1JZ-Rolla]

All pretty much done now thanks Chuck, was just the one guard that needed particular attention, where it couldn't be beaten any further from the other side:






Its not perfect, but good enough for my application Hoping we get a break in all this rain/humidity so I can finish the job off in the next week. Need to make sure i leave enough time for each stage to fully cure/shrink back/release solvents, especially since i'm going two pack top coat over acrylic single pack primers.

[o_man_ra23]

My Workquip works happily at 20ish psi using high fill primer with the 1.8 nozzle. When I had the pressures up too high, there was massif overspray, orange peel and farkall coverage for the quantity of paint used. I dialled down the regulator, and viola!! Orange peel almost completely disappeared (thinner coats had no orange peel), coverage was fantastic, and overspray was pretty well zero.

[1JZ-Rolla]

20psi static, or 20psi dynamic?

[o_man_ra23]

20psi at the regulator with my empty gun opened full. About 25psi at the regulator static, however that's not a real accurate measure.

[1JZ-Rolla]

Ah, that makes much more sense then. thanks

[TurboRA28]

So, what is a good brand bog to buy? Something that is kind to dummies who haven't used it much before. Last attempt I found the stuff was going hard before I could get it on the body (being used outdoors) and then when I sanded it had lots of holes/pockets in it.

["Z" UTE]

So, what is a good brand bog to buy? Something that is kind to dummies who haven't used it much before. Last attempt I found the stuff was going hard before I could get it on the body (being used outdoors) and then when I sanded it had lots of holes/pockets in it.

Joel, I use PPG Galvaplast microfine filler, next to no air bubbles, and when sanded leaves a very fine paintable surface.

If the bog is going off too quick, back off on the quantity of hardener.

For vertical surfaces however you want the bog to harden quickly, so add more hardener. The recommended ratio is only a guide. I suppose you have to start with a baseline and then adjust for your conditions. After 4 cans of bog, I would have a spare tube of hardener left.

I would probably never mix more than 3 heaped tablespoons of bog at any one time. Mixing more than that and the stuff goes off before you can use it all. Your first application is normally the best, going over the bog as it starts to go off will result in the bog pulling from the job.

If you have been a bit skimpy in an area and it has gone off, you will have to sand that bog to remove the skin that forms on top. ie. You can not lay fresh bog on top of just cured bog unless you sand that previous layer.

I mix my bog on a piece of 3mm MDF. I use a single edge razor blade to scrape the board and the applicator clean just before the bog sets. If the stuff goes off, use a flap disc on a grinder to tidy up the board.

The flap disk on the grinder is also the easiest way to quickly knock back and shape the bog.


cheers Chuck.

[o_man_ra23]

Bog will go hard before you can use it if you don't work quickly. Try a tad less hardner.

I have been using U-Pol Hotshot. It doesn't leave much at all in the way of air pockets (usually get zero air pockets), and once sanded it leaves a really smooth surface. It will go off really quick though, so you have to work fast (and as Chuck said, do small bits at a time).

[TurboRA28]

Hi all, i've started reading this thread from the start and learning lots.. But a few questions have come up for me..

With painting the Coaster bus it's so friggin big, so will have to be done outside. How am I best to tackle it? In stages? eg. paint one side a day? I am worried I might miss the flash off point for the 2nd coat if doing the whole thing. So either a whole coat, sand, another coat next day or something? Or a few coats on one side one day, other side later? Just trying to get some ideas on the best way to do something this size.

Also I need to remove the windows to do some repairs.. Am I best to remove windows, repair, prime, colour around the edges, then fit the windows back in and mask them up with I do the rest of the bus? As it is outdoors I can't leave the windows out for an extended period of time.

Thanks
Joel

[o_man_ra23]

If you can tape some tough plastic/paper sheet to the inside of where the window was prior to painting that side, that would be best. If not, then your suggestion would be the preferred option. A bit of thick venitian blind cord under the lip of the seal will help to hold it up to mask/paint. That way the paint join is under the seal and not visible.

What is the maximum time between coats which your paint will allow?? Usually it is a few hours. You should be able to complete a coat (even on a coaster) in a few hours. If you start real early in the morning, you should be able to get 3 coats in within a day easy. Assuming you are using a solid topcoat colour of course (clear over base could be a struggle since you need several coats of each)

[TurboRA28]

I'm using the Proteck iso free stuff.. just a flat colour.. Is that COB?

["Z" UTE]

Hi all, i've started reading this thread from the start and learning lots.. But a few questions have come up for me..

With painting the Coaster bus it's so friggin big, so will have to be done outside. How am I best to tackle it? In stages? eg. paint one side a day? I am worried I might miss the flash off point for the 2nd coat if doing the whole thing. So either a whole coat, sand, another coat next day or something? Or a few coats on one side one day, other side later? Just trying to get some ideas on the best way to do something this size.

Also I need to remove the windows to do some repairs.. Am I best to remove windows, repair, prime, colour around the edges, then fit the windows back in and mask them up with I do the rest of the bus? As it is outdoors I can't leave the windows out for an extended period of time.

Thanks
Joel

Joel, Owen has hit the spot with the cord under the seal to raise it so the paint join is under the seal. If your masking skills are really good you could avoid this, but not many are that good. Plastic is a pain, as paint will sit on top and dry, when you shoot the next coat the dry paint will flake off and adhere to your new coat, not the best effect in a top coat.

For a beginner, I would suggest doing one side and the front or rear first day, I would be pretty confident that by the time you finished one coat on the side and rear of a Coaster, the part where you first applied paint would have flashed off. That becomes your starting point for the next coat. There would be nothing worse than having to sand between coats on something as large as the Coaster. If you are using a solid colour and you count the coats on each section, there will be zero difference in the depth of colour and zero colour variations. At one time I had a bit of a time crunch, but still had to paint a car, each lunch hour I would mask off andpaint a panel or two, took 2 days to paint a Mini, but being a solid colour there were no problems.

good work so far, cheers Chuck.