Water based HELP NEEDED

[buybuybuy]

Hi guys, firstly can I introduce myself as a first time user to not only this forum but also water based paints and wondering if some of my questions could be answered.

1. how many litres of paint, roughly, are required to spray a saab 9-3.

2. what heating methods do I need to use and at what temperature. Can I use 3 or 4 fan heaters in my workshop instead of using airdryers and red rads.

3. roughly how much is it per litre of waterbased basecoat.

4. are the manufacturers stopping production of cellulose.


I know the above questions may seem stupid but I was trying to convince myself that they wouldnt go ahead with waterbased paints and have always sworn by 2k. Really not sure I will be able to get on with water paints.

 

[Omniata]

Welcome to the forum!!

I wouldn't have though drafts from fans would be a good idea as it may cause some of the paint to dry before it hits the car....

 

[jaykay]

i've never used waterbase,cant get my head around putting water on metal.
but i would tend to paint it first then put heater on.
oh and get spec sheets.

 

[steveo3002]

youd want a warm garage /room to spray in , this time of year would be too cold for a couple of fan heaters , remember the panels need to be room temp too

in the paintshops they use air blowers to dry the water basecoat , you could stand around and let it flash off , or blow on it at low pressure with the spraygun at half trigger , massive amounts of heat dont help alot as you need to wick the moisture into the air away from the paint

best find out what brand /product you are using , some of the water base colours cover very very well

 

[Antsuno2]

waterbase is expensive, use 2k base, until they force it off the shelves,(years to go) loads better, its the laquer that kills you, Ant!

 

[joe666]

you need it about 18c ideally though in summer the booths i used to paint in used to run around 25c, air movement not heat dry's waterbase to much heat skins it over causing no end of problems when you lacquer it.
You need to blow it dry the longer the better id say 30 mins in a workshop. if you can get air movement across the panels not at the panels itll dry better and quicker.
The key to getting a good layer of basecoat on is to drop coat the panels first (a really light mist all over) then make sure its dry before applying a wet coat, (it goes on a different colour to what it drys so dont be alarmed while spraying) then dry it then a drop coat (depending on colour)
it covers well and hides a multitude of sins just make sure its dry between coats as if not you will have a big mess to clean off

total respray including door shuts ect id say 3 litres or more depending on colour there a big car really

waterbase is expensive if you get ppg or sickens or similar itll cost a fortune, depending on colour again some of the cheap ready for use stuff you can buy is **** though so be warned..

its easyer to go get solvent basecoat while its still available if you need to flat dirt out ect youll find it easyer to do
as for stopping production no just limiting it
hope that makes some sense ........

 

[buybuybuy]

I dont suppose theres anyone near Stansted who works as a panel beater who I could come along and have a quick look at how they do it?

 

[dunsdale]

You really dont want to painting large areas in waterbase, outside of a booth, as Joe666 mentions its all about air movent, the more air movement the quicker water base will flash off.

Waterbase is more forgiving in terms of re-actions as it is non aggresive due to having very low solvent content. But it is also harder to apply.

When i say harder that is getting a nice uniform finish, no tiger stripes or mottling, solvent is easier and you can flat it off and re-apply if there are any problems much easier than you can with waterbase. As it takes longer to flash off you will probaly pick up more contamination of the base coat dust dirt etc.

Afull respray in water outside of a booth will take all day. Solvent would be much quicker and easier.

Not being a smart ass but panel beater's dont paint, generaly they panel beat and the painters do the painting.

 

[buybuybuy]

Are there any friendly painters who could let me have a look for a moment at how they do it. Probably not but thought I'd ask anyway and I could bring some cakes and put the kettle on.

Cheers

 

[StainlessBloke]

One thing that is critical when applying water based basecoats is the humidity in the spray booth/area. If it's too low, you can find the paint flashes off as soon as it hits the substrate which is obviously not ideal.

A lot of rubbish is talked about the health and safety aspects of water v solvent (I worked in Industrial/Automotive paints for may, many years) in these types of application. Water based basecoat still contains a lot of solvent, it's hardly 'environmentally friendly' which is what manufacturers would have you believe. The biggest H&S issue with spraying is the lacquer (as was mentioned above). It's chock full of isocyanates and far more debilitating than the basecoat.

Is was thought for a time that solvent basecoats would be phased out entirely, but this is now not the case - a number of major automotive painters installed incineration systems on their paint plants - basically, this reduces their emissions to zero, which is far more environmentally sound than simply switching to waterborne.

Supposedly, there are some reasonable water based lacquers out there now, but I'm yet to see anything comparable to solvent based counterparts.

Hope this is helpful.

 

[pennytrucker]

Interesting discussion.

I am led to believe that a lot of the SMART repair guys are using Water Basecoats, but I wonder what they do for a Clear coat (lacquer)? Since a lot of this work is done at customer premises, they do not have a booth and probably not an air-fed mask, so you would think anything Isocyanate based is a no-no?

I have heard before of non-Isocyanate based products (I assumed base & clear), but could never find much detail and seem to recall they were never reckoned to be much much good. Maybe these were actually early water-based products.

Also begs the question what you get in an aerosol clear coat. Presumably it cannot be as Toxic as an Isocyanate clear, but it is it as resilient (i.e. performance as a protective coating to the Base coat)?

 

[StainlessBloke]

Interesting discussion.

I am led to believe that a lot of the SMART repair guys are using Water Basecoats, but I wonder what they do for a Clear coat (lacquer)? Since a lot of this work is done at customer premises, they do not have a booth and probably not an air-fed mask, so you would think anything Isocyanate based is a no-no?

I have heard before of non-Isocyanate based products (I assumed base & clear), but could never find much detail and seem to recall they were never reckoned to be much much good. Maybe these were actually early water-based products.

Also begs the question what you get in an aerosol clear coat. Presumably it cannot be as Toxic as an Isocyanate clear, but it is it as resilient (i.e. performance as a protective coating to the Base coat)?

Got to be honest, I have very little experience with aerosol based products - little that I do know is based on hearsay. Much as you said really; when compared to a decent 2k lacquer, they're not up to much in terms of finish or durability.

I know of at least two major paint companies who have spent an awful lot of time and money trying to develop a decent water based lacquer but with little success. They eventually moved the funds into looking at producing low VOC versions of conventional clearcoats.

 

[buybuybuy]

Well I had a go at spraying some water based paint and can honestly say it is the most wierd paint to spray with. It was probably more to do with the fact that I didnt like the sound of it.

The stuff smells like poster paint and seemed like I was being ripped off with the price of it at £30 per litre, mixed!!. It was very nice though to use a bit of fairy liquid afterwards on my hands and watch it come off with no hardwork or brillos being used. The smell is non existant when spraying

It goes on a completely different colour to what it dries like and you can almost see through the wet coat until its dried. VERY STRANGE INDEED.

I really think it will take some getting used to and will invest in a few litres to practice on old car panels.

What do you rub the waterbased paint down with because it kept scratching too much even with 800 grit.

 

[joe666]

800 you need 2000 or 1500 minimum
waterbase drags when flatted a gentle one direction rub is best just make sure its perfectly dry

 

[MG David]

Can you wet flat water based or do you have to do it dry.

 

[StainlessBloke]

Can you wet flat water based or do you have to do it dry.

In my experience no. It's more difficult to dry flat than solvent too.

 

[dunsdale]

Can you wet flat water based or do you have to do it dry.

Some waterbase types you can flat for instance spies hecker waterbase can be flatted wet, but not with water. You use panel wipe.

Lesonal water base cannot be flatted wet i have tried all sorts with it, it can only be flatted dry. If you do have the misfortune to try and flat it wet it will just pick up and strat rolling of the panel.

 

[joe666]

i think the best thing is to prep it properly in the first place then you wont need to flat it at all

 

[Antsuno2]

should be plenty of guides on youtube, Ant!