The Spray Painting Thread

[hamgatan]

OK After Reading all 41 Pages, I think I'm ready for it.

I just have three questions,

1) There are places my Random Orbital Sander has trouble reaching (I.e in the door jambs). For places that are not direct exterior panels, can a wire wheel and angle grinder be used to take the paint off? I realise this will leave big scratches in the metal but its pretty tricky to get in there otherwise. Most of those sections usually have weatherstripping over them or rubber seals..

2. Windshield edges. I'm not taking out my windshields, so whats the best way to strip the paint back on the very edges of the windshields? Ive removed the rubber seals, but its tricky to get in there and take back the paint. Same goes for the back of the bonnet and boot lid.. tricky to sand with the reinforcement backing on it.

3. Is taking it right back to metal a bad thing? I would have thought it would be better to do so but some negatice nancys have been crowing otherwise.. I've already taken a fair bit of the drivers side back to metal already.

Chris

["Z" UTE]

Chris, you can buy a "plastic" wheel, the fingers on the wheel are impregnated with abrasive. Fitted up to an electric drill they work a treat. I buy the Josco brand from Bunnings. Wire wheels are the pits, you are forever pulling little bits of wire out of your clothes.

With the screens removed, I use the plastic wheel. What sort of car are we talking about here? Rubber out but screen in?

Back of the bonnet and boot had me stumped for a bit I was thinking of trailing edge. What you really meant to say was the underside of the boot and bonnet. You will find that there is precious little paint under the ribbing, and a quick wipe with 800 wet and dry will be all that is required for that area to accept a coat of paint. Before fully painting the underside of the boot and bonnet, I would blow a coat of paint under those supports. At this stage you should also paint the underside of the skin that is visible through the other various holes.

Be aware that is is absolutely critical to remove ALL the oilmist and grease from the underside of the bonnet before sanding there. I generaly use a litre or so of degreaser, a stiff brush and then a high pressure washer as a first step. I then follow it up with a bucket of hot water with a couple of cap fulls of sugar soap, and a paint brush to really get under the ribbing, then flush it all out with the garden hose.


If the original paint is not flakeing off, and the body is sound under that paint, then there is absolutely no reason to go back to bare metal. But if that is what you want to do, go ahead. Just note, that you will be taking off the original metal protective coat, so any bare metal will have to be phosphated before any primer or sealer goes on.

cheers Chuck.

[o_man_ra23]

Hamagatan, if it is a glue in screen, then use some piano wire and remove the damn thing. It will be a zillion times easier to do a bare metal with everything stripped properly. I don't think a bare metal without a thorough strip down would really be as good as you expect... as that is where the rust will start from....

[hamgatan]

Chris, you can buy a "plastic" wheel, the fingers on the wheel are impregnated with abrasive. Fitted up to an electric drill they work a treat. I buy the Josco brand from Bunnings. Wire wheels are the pits, you are forever pulling little bits of wire out of your clothes.

+repped. bought one of these today and gave it a burl... shits awesome... took literally all the paint off my drivers side door sills and strips and left no damage. got through the entire drivers door frame, and some of the rear drivers side done too and the wheels half used. i reckon two maybe three of them to do the whole car edges..

i realise taking it back to metal ill have to etch prime it but i think its better that way. this is on my JZX90 incidentally..

you're right about the windscreens boys.. im just being lazy.. ill take them out tomorrow night. guitar string do the same thing? just a bit paranoid about breaking it thats all..

well ive got about 35% of the car back to bare metal so far.. keep soldiering on i guess

[o_man_ra23]

The only one you are likely to break is the front windscreen, as it is laminated rather than tempered glass. But front windscreens are readily available from windscreen shops, and fitting a new one will give you new, unparallelled vision, and windscreen wiping abilities.

Guitar string may be too thin. You really want either mono, or twisted, whereas the thicker guitar wires tend to be spiral wound correct?? I guess you could braid a few thinner ones together and use that.

[shoom]

1.4mm is fine for acrylic right?

I just switched to a DeVilBiss 1.4mm HVLP gravity feed but plagued by orange peel in the finish. I get really even coverage and excellent gloss but orange peel. I have never had this issue before with any of my other cheaper guns (Star suction feed 2.0mm, unknown brand gravity feed touchup 0.8mm).

I did have to increase the line pressure above what the box said because it just wasnt atomizing at the lower pressure they stated. But I dont see how this could affect it.

Suggestions welcome

word, they are the rolls royce of spray guns! (coming from someone with a 70 buck star knock off hehe) I've sprayed a couple of boats with polyurethane 2 pac in my time so I know a little about spraying .. remember its alot like welding , nice flowing straight lines with a good 30% overlap of the last pass keeping gun parallel to work, press / release trigger with gun in air away from edge of job coming across to meet job at start / finish of a horizontal run.

I got this neat cheapie gravity gun from fibreglass and resin supplies for $30 with 2.0 mm tip and it is an absolute beast for bombing on the high build , total kick ass timesaver no good for anything but though.

I am wondering if I can use the poly u400 for painting cars given the right undercoat as its so durable being designed for marine use and I have lots of it lying around / can get cheap. would be ok for my daily corolla van.

[ian]

i have seen it done on many commercial vehicles without a problem
the only thing to consider is using a good isolator sealer before the color

["Z" UTE]

[QUOTE=hamgatan;1090478.........

you're right about the windscreens boys.. im just being lazy.. ill take them out tomorrow night. guitar string do the same thing? just a bit paranoid about breaking it thats all..

[/QUOTE]

Drop into your local auto parts store, or Bunnings, and buy yourself half a dozen of the cheap plastic box knives. (You are going to break a couple.) The mid size blade ones, extend the blade to max length to get max flexibility. Attack the urethane from inside the car, a few swipes in each area instead of trying to get it cut through all in one go. Continue all the way around the screen, and it will almost fall out.

Pull wire in the hands of a novice is almost a guaranteed broken screen. Windscreen fitters use a biamond encrusted wire, or a 90deg bent blade double handled pull device to cut the urethane. Trust me, I offside for the best windscreen fitter in Canberra.

cheers Chuck.

[o_man_ra23]

Chuck, you are right that the risk of breaking the FRONT windscreen is high with a novice doing the job (regardless of method used). BUT the risk of cutting your damned wrists with the box knives is probably higher. I personally would rather the windscreen break. Your chances of breaking side/rear glass is somewhere between low and not very much.

I am pretty sure you can buy the 90 degree bent blades reasonably easily. Pulled quite a few screens out of wrecks in my younger days, and the most success was with piano wire. The thicker single strand stuff lasted the longest. Takes 1 people, and you need a thick coat hanger to make a hole in one corner to start you off.

[Steve M]

Last time I took big windows out (windscreen and rear window) I left it in the seal and flipped the seal and window out as one by hand from inside the cabin. This worked a treat, the seal is not as solidly mounted to the inside of the body of an RA23 as it is on the glass.

Admittedly I had already cracked (but not distorted) my windscreen trying to get it out before my brother told me about this method but it worked a treat to finish the job and to remove the rear window.

No tools were required except to remove the interior pieces that were in the way. My seals were pretty new and still flexible. I don't think this would be as easy with old, hard seals.

Getting RA28 hatch glass out is much more painful. Wires/string and stuff were required for that one.

[Steve M]

I recently changed to protec 'premium' acrylic thinners from their standard acrylic thinners and it has given me a beautiful gloss from the gun. I'm not 100% sure whether it's the thinners of the position I've been spraying in (vertical as opposed to horizontal surface), but I'lll be sticking with the premium (slower evaporating) stuff.
It appears as though each coat has better thinner penetration into the coat below it. Hopefully this will make for a longer lasting and chip resistant coat. I reckon the paint is curing better too. It feels harder after three days that the paint I did earlier did after a week. It could just be the gloss feels better than the clear overspray, I don't really know, but I'm Happy!!

[trd_st184]

A tip with spraying 2 pac is to spend the money and get a decent mask too with the correct filters.

I've resprayed 1 car (failed attempt) and my main issue was to do with the clear coat which was used with the wrong gun and ended up coming out like silly spray out of one of those cans.

Another thing was that I stood too far and used the same techniques as spraying with a can which was fast sweeping motions. This won't work with spray guns.

More pics please

[o_man_ra23]

Steve, the string technique is used for glued in screens as per the JZX90 that Hamagatan is doing. The technique you described is for rubber mount screens, and is correct (protects the edge of the glass). If your seal is hard and stuffed, then piano wire won't help... you need a stanley knife, and cut the rubber along the glass edge.

Sounds like a good result with the thinners though Steve.

[Steve M]

O Man,

It hadn't even occured to me that some people live in an age where windscreens are glued on. I still live in the dark ages, and am happy there.
Thanks for pointing that out. It may be useful in the future.

[o_man_ra23]

Don't worry mate, neither of my cars run glued screens, I think even my ute has rubber seals