Paint Spraying Equipment

[Reddi-Eng]

Reading the many stories of restorations on this forum and talking to other owners off the forum I know that many have paint sprayed their own cars. Some are no doubt experienced sprayers, others have done it for the first, and possibly last, time.

I have another GRP bodied car currently finished in gel coat, which needs panting. Is the advice "don't do it yourself" or "with the right equipment and acceptable finish can be obtained"?

If the latter, what is the right equipment?

[Greybags]

With a bit of practice and some reasonable equipment you can get a good finish... The better the preparation the better the fininsh..

The small little compressors dont really have the air delivery, and with spraying it's not the pressure that matters but the amount of air (CFM cubic feet/minute), so I use a 2.5Hp 14CFM with a 50Litre tank jobbie that seems to manage quite well.

The better the gun, the better the finish, and although I would love a Sata gun at £200, I have 2, one that cost £25 with a large needle which I use for the thicker primer, and a £40 one with a finer 1.2 needle for the top coat.

They give reasonably good out of the gun finishes with out the need for a lot of polishing at the end.

Most importantly is to make sure the cfm of the gun is well within the cfm range of the compressor...

Have a look at the Practical Classic web about paint use ... Apparently 2 pack is no longer the deadly stuff it used to be, and I would love comment from the more professional sprayers among us as to whether what they say is correct...

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With all the mechanics completed, and the bodywork fast approaching the paint stage, I could really use a couple of paint articles, especially on the use of water based paint.

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martin thaddeus



Joined: 30 Aug 2008
Posts: 146
Location: crawley
Posted: Wed May 27, 2009 11:55 pm Post subject: water based paints

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Hello
sorry i havent pick up on this question before.
Water based paints are not easy to use .most of the guys i have spoken to who use them say it takes a while and during that initial time things will go wrong.

the upside of water is the lack of solvent make them supremly stable and non reactive. that and the lack of polution. but this is offset by the 2-pack lacquer you have to lay over the top to protect it.

Water obviously is slow to dry and this means more chance of crap falling onto the job. esspecially if you use a blower to force dry it.

But the main problem for the man who is new to the product is putting the clear lacquer before the basecoat is totally dry. This then leads to the two components failing to bond. it messy and time consuming to put right.

Modern 2-k basecoats contain no isocyanate and are safe enough to use. You could use a decent 1-pack clear to keep the toxin level down, but i would suggest that you use a good 2-pack primer for the sake of having a sound and stable foundation to lay the paint on.

IF you really want to use water, then go and get friendly with you local bodyshop, see if they will let you chat to the painters.

Good luck. martin

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arfursixpence



Joined: 04 Jan 2009
Posts: 198
Location: Under a car, probably.
Posted: Thu May 28, 2009 2:57 pm Post subject:

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There was an article on using water based paints about 12-18 months ago (maybe a bit more).

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TerryG



Joined: 04 Mar 2008
Posts: 762
Location: East London somewhere.
Posted: Sat May 30, 2009 10:18 am Post subject:

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There was an article on painting with rattle cans september '08. well worth a read and following the advice gives a good result!
_________________
Understeer: when you hit the wall with the front of the car.
Oversteer: when you hit the wall with the back of the car.
Horsepower: how fast you hit the wall.
Torque: how far you take the wall with you.

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Greybags



Joined: 06 May 2009
Posts: 5
Location: Plymouth
Posted: Tue Jun 09, 2009 8:33 am Post subject:

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Quote:
Modern 2-k basecoats contain no isocyanate and are safe enough to use.


Just to clarify what I think you are saying.

There is no need to worry about using the water based stuff as the 2K stuff is no longer the health hazard it was????

So I can happily spray with 2k in the garage without killing me or the neighbours....

Sorry to appear thick about this, but it does seem to change what I have read so far..
_________________
Gilbern Invader Mk11 Estate..
Most of the pile of bits now reattached to the car

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martin thaddeus



Joined: 30 Aug 2008
Posts: 146
Location: crawley
Posted: Tue Jun 09, 2009 9:44 pm Post subject: paint safety

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Hello

2k basecoats have never actually contained isocyanate. Its the primers and clearcoats which are nasty. the basecoats do have a very high solvent content and the new EU compliance rules are all about VOC rather than specific toxins. some of the new single pack primers are pretty good and the newer clearcoats are brilliant. The latest 2k compiant stuff uses new hardeners which mean that what was acrylic is now polyerethane and its safe and legal with the new hardener, but not with the old. it'll do your head in thinking too much about it.

I say use a 2k primer and 2k base and then top with either a good single pack clear or take the plunge and go with 2k clear. to keep the toxin level down you can alway brush the 2k primer on to the repairs then flat it with 180 dry. on to this you then spray a thin coat of primer -which could be 1k. this is then flatted with 600/800 wet. by double priming like this the top coat has nowhere to sink. hope this helps. Martin
Posted: Wed May 06, 2009 12:27 pm Post subject: Refininshing especially with the new paints


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[rocketman]

The approach that I took when I got to the painting stage on the Mk1, was to go for 2 pack paint. 2 pack is very durable allowing you to flat of the car when finished which removes any orangepeel/runs which you are bound to have, you then use an electric buffer and cutting compound to achieve a show car finish. I bought a Fuji HVLP spray system for the paint, HVLP is very controllable and produces half the overspray of conventional spray systems. As 2 pack is cyanide based I used my 9 CFM compressor to feed an air fed mask. My garage was also positively pressured with a fan blowing through a paper filter to help keep dust out, the 'exhaust' was a small open window. This was the first car that I have completely sprayed, there is a big learning curve for technique but like everything if you are willing to put the effort in you will get a good result.
If I had not gone for 2 pack I do not think i would have achieved anything near to what I have and it will stay good for many years. I think that water based is a bit of a non starter for amateurs due to the requirement for substantial drying systems, infrared heaters etc. Lots of effort required but I will be looking forward to painting the Mk3 that I have for rebuild.

Stu.

[Reddi-Eng]

Further to the replies above, and thank you very much for your comments, the December edition of Classics Monthly has a feature on "Learn To Spray" and a review of Spray Guns which both help in understanding the process.

Also found the following site (other sites are available ) which may also be of interest.

http://www.austinsevenfriends.com/paint.htm

http://www.hse.gov.uk/pubns/indg388.pdf

http://www.mig-welding.co.uk/spray-painting.htm

http://freespace.virgin.net/tommy.sandham/twopack.htm

http://homepage.eircom.net/~hondabros/SPRAY_PAINTING_TIPS.html


Any other input most wlecome as it add to the knowledge base.

[trippdl]

I had my Genie (professionally) resprayed about a year and a half ago, with two pack. I called a local shop a couple of weeks ago, to see about buying some touch-up, and was informed that 'due to changes in the EU regulations, they can no longer supply two-pack', and would only offer to do a water-based touch-up for me.

I'm not sure if this is for real, or if they are trying it on, but might be worth checking.

I was told a couple of years ago that there were exemptions to the various prohibitions for classic cars, but don't know the current situation.

For my next project, I will get a shop to do the water-based job, on the basis that it is the most flexible, and probably the thinnest coating, in the hope (vain, I am sure) of never seeing another stress crack.

I remember, back when I had a TVR, resolving that the next one would have to be painted off-white, so that the colour would match the dried polish stuck in the cracks...

[Waylison]

Hi Dave.

I use a clear polish called 'ICE'. It's for sale in most car places including Halfords. It's a bit pricey, but well worth it.....let me explain.......it's a clear liquid that you put on with the supplied pad, very thinly and it doesn't matter if it goes over the trim or screen rubbers, in fact I find it helps keep them black and shiny, you then use the supplied micro fibre cloth to rub off, very quick, a deep shine and no white residue at all! I've used the same bottle four times now and still got over half left. Last time Roger Spares saw the car he commented...." how do you keep it so shiney'....so now you know.

Cheers,

[Greybags]

My understanding of how it was explained to me, of the new rules is that small users, restorers etc can still buy and use cellulose and two pack, which apparently is no longer the serious health risk it was since the changes, but the pro's can only use water based...

So if you do it yourself you can use 2K or celly, if you use a pro restorer, he can use a paint in keeping with the originalality of the car, 2k or celly if that's what you want, but a pro normal body shop can only use water based.

I know there is far more to it than this and there are lots of differences, but this is how it was explained to me by the local paint supplier I use, who can and does still supply celly, the latest 2k stuff (see the Practical classics bit) and others all at a most sensible price.. 2k £20/litre.

There are a lot of places on the web supplying mail order as well.

Grahame

[Reddi-Eng]

With advise from this forum, Phil Ivimy's excellent article in the latest Rarebits, and recent features in the Classic Car press I'm building up a good picture of what needs to be done to achieve a good spray result. There seem to be three ingreedients...

1. Preparation - a sound base which the paint will stick to.
2. When & Where - When its warm in a large dust free proctected area
3. Plenty of paint and flat/polish afterwards ie unless you area professional sprayer, spraying alone will not give a good finish.

Starting from scratch equipment, paint and materials to build a suitable environment would seem to be less than £500 whereas a profession job will be anywhere from £2,000 upwards, even with preping it yourself.

Sounds like a doable job so long as you don't want/expect a concours result. Having said that, and seen Phil James's MK1. if I could get near that I would be more than happy.

Does that sound like a fair summary?

[Gilbern74]

Been reading up on this myself.
There's a good write up on the TVR site here

I plan to do the prep myself up to the first guide coat. Then i have a local place lined up to do the paintwork.
I can't wait till its painted but expect it to be 18 months away



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