57 replies to this topic

[Shifty]

Hi, went to my local paint store today to get some 2pack for Humphrey(bascoat and clear in Storm Grey).

The paint they now sell is water based rather than the solvent based 2pack. Are there any differences in the way that this behaves compared to the old stuff.

I am using a devillbiss Gti gun with a 1.4 set up.

Normally I would give the car a light mist coat first, allow this to dry for about 30 mins and then give it 2-3 more coats with 30 mins inbetween.

I would then wait 2hrs before applying a couple of coats of clear, with 30 mins between coats.


Before applying the paint I would heat up the garage using a propane heater, I have never used this whilst painting the car because of explosion risks!!

Since this paint is water not solvent based can I use the heater?

The clear is 2 pack.

Any hints or tips based on the above info would be much appreciated.


Thanks

Seamus

[In-a-mini]

water based paints are not ideal for diy/home painting the water takes so long to evaporate you need alot of air movement not just heat. The times you gave for the solvent painting were a little long for solvent i leave about a 15-20min flash of between coats and not much more before clear coat if you leave it too long the clear may not stick so well and a chance of lifting later are higher.
also about the same times for solid colours. You can still get solvent paints but not usually from your normal supply due to the new legislation but over the net and ebay seems to have quite a few (sold usually not to be painted on cars. WINK WINK). So thats probably your best bet.
But if it is a small area you are doing you can get away with water based but remember it requires different methods like different panel wipe no bare meta primer has to be well cured no remaining solvent. you will have to force dry it like blow with gun half trigger. Some gti's are not meant for water based parts of the guns are different they work but you have to clean and dry them very carefully.

Edited by In-a-mini, 29 February 2008 - 09:38 PM.

[Shifty]

Hi, thanks for the reply.


Unfortunately I have already bought the paint!!

Is there any advantage to using the space heater whilst painting?

Seamus

[In-a-mini]

I allways use a space heater to heat the room then off when painting as you said i surpose you can use it more for the water based paint as there is no solvent but might kick up some soot might just be my one but it was a diesel one a propane one might be better. but i would just do what you normally do then blow between coats to get the air flow you need you will see the water thinner and binder evaporate as you do it.

[Shifty]

I was just getting the hang of 2pack and then they go an change it!! Bloody Government.

Thanks for your help, I meant to ask at the painshop but it all ended up being a rush around.

I will let you know how I get on.

If airflow is the answer maybe i should have painted it tonight as its blowing a gale!!

Thanks

Seamus

[In-a-mini]

yeah i know what you mean i painted something yesterday in good old solvent went out tonight to putt all my stuff away and half my garage flew about as i opened the door lucky i re nailed the roof down recently. Good luck with it post some pics when your done

[Shifty]

At least it can't look much worse than it does here!!

http://www.theminifo...mp;#entry857286


Seamus

[jack_marshall]

If your gun is just a Gti then I dont think its the best idea.

If its a GtiW, it should be suitable for water based.

Make sure your gun is free from an old solvent paint and run some waterbased gun wash through it just to make sure, or you get some real funny concoctions coming out!

Regarding solid colours, you can still get them in good old trusty 2k, but in a form called high solids, and in my opinion, its wonderful stuff!

[panelbeaterpeter]

Gti's are fine for water, I use one now and again and it's better than my 1.3 GtiW. 1.4 GtiW is best though.

[Shifty]

I'm hopefully going to try and paint tomorrow, quite excited about trying something new. Just hope it lasts!!

Thanks for all of your advice, keep it coming because i need it all!!!


To recap the best way is

Light coats with about 20 mins inbetween

Use waterbased gun wash and panel wipes

Try and get some air flow onto painr

Seamus

[panelbeaterpeter]

Just had a quick skim through the thread, I don't think anyone has mentioned you need warm air blowing at th paint in order for it to dry. It will take hours otherwise. A hairdryer would probably work, or a hot air gun, but they tend to throw cr@p onto the paint. When you spray it in a booth you have a special air blower that blows warm air over it, it's no good at all without a booth, I wouldn't even attempt it without one. Also it's just about impossible to flat down unless it's left for a day or so, so if you get dust in the basecoat, you're screwed. Also don't try wet flatting it or it'll melt

[Shifty]

Hmmm, heard the same from a mate down the pub tonight.

However the paint store guy reckoned that it should be the same as 2pack(lechler)

Still got the paint and gonna give it a go.

Seamus

[panelbeaterpeter]

No way is it like solvent Lechler, that's what I used at work before the water based rubbish came in, it's as far away from it as possible!

If you really want to use waterbase, with the gun set up to 2 bar, bang on one full coat to cover, let that dry, put on an 80% coat, then when that's dry, thin down the base with 10% water and apply a dust coat, keeping the fan 45 degrees to the panel, turn the pressure down to 1.5 bar and spray it diagonally, moving the gun slower than you would for previous coats. This way the paint rolls over itself, and lies nicely with no mottlyness.

[Shifty]

No way is it like solvent Lechler, that's what I used at work before the water based rubbish came in, it's as far away from it as possible!

If you really want to use waterbase, with the gun set up to 2 bar, bang on one full coat to cover, let that dry, put on an 80% coat, then when that's dry, thin down the base with 10% water and apply a dust coat, keeping the fan 45 degrees to the panel, turn the pressure down to 1.5 bar and spray it diagonally, moving the gun slower than you would for previous coats. This way the paint rolls over itself, and lies nicely with no mottlyness.

Thats the kind of advice i need!!!

Thanks Peter, kind of looking forward to seeing what kind of mess i make!!!


Seamus

[jack_marshall]

Just had a quick skim through the thread, I don't think anyone has mentioned you need warm air blowing at th paint in order for it to dry. It will take hours otherwise. A hairdryer would probably work, or a hot air gun, but they tend to throw cr@p onto the paint. When you spray it in a booth you have a special air blower that blows warm air over it, it's no good at all without a booth, I wouldn't even attempt it without one. Also it's just about impossible to flat down unless it's left for a day or so, so if you get dust in the basecoat, you're screwed. Also don't try wet flatting it or it'll melt

You can flat it using spirit wipe and 1200-2000 though, instead of using water.

Thats what I've used when Ive got bits of C**p in the base and it didn't melt it away.

Waterbased basecoat definately doesn't flat like 2k basecoat did though. So be careful if you have too.

Good luck! Got a feeling you may need it!