Gun Advice For Dulux Eggshell Onto MDF

[EViS]

Hi all,

Compressor aside, what gun (nozzle size and cfm) would you recommend for painting MDF with Zinsser Bin (shellac based) followed by Eggshell topcoat? The topcoat is water-based (with an Acrylic binder) and the datasheet recommends diluting upto 1 part clean water to 2.5 parts paint for air-spraying.

I am being led to believe (from research) that I need a 1.8mm nozzle (sounds a tad large), but unsure on the required cfm? Would I need a HVLP gun for spraying these paints?

 

[jaykay]

there are guns and compressors for spraying these sort of paints.
dont think you'll have much luck with a regular set up. they keep clogging at the gun.

 

[EViS]

Are you referring to either an airless setup or a turbine-driven HVLP setup?

I'd rather get myself a compressor which I can then use for other things, as opposed to either of the above which cannot be used for anything else...

You wouldn't know what sort of gun I require, would you?

 

[jugs]

Are you referring to either an airless setup or a turbine-driven HVLP setup?

I'd rather get myself a compressor which I can then use for other things, as opposed to either of the above which cannot be used for anything else...

You wouldn't know what sort of gun I require, would you?

Ask the Dulux Tec dept

 

[EViS]

I've had a chat with Dulux and they have no recommendations for spray tips. Maybe I should go with an automotive spray in this case...

Can you get an 'eggshell' automotive paint? If so, what manufacturers do you recommend to buy from?

 

[mike os]

tip size is more a function of paint viscosity & pressure, low pressure = big tip

high visosity = big tip......

"Application Methods – Shake or stir before using.
Eliminate all sources of ignition. In most cases only one
coat is necessary to prime most surfaces. If excessive
absorption occurs over very porous substrates a second
coat may be necessary. Spot priming is recommended
only under high-hiding topcoat paints. For best results
prime entire surface before painting. Keep container
closed when not in use. Do not thin this product.• Brush, Roller or Pad – Use natural or synthetic (nylon,
polyester or blend)
• Airless Sprayer – Use .011” – .013” tip @ 800–1,200 PSI
• Conventional Sprayer – Spray at 45 – 55 PSI"

my guess 1.8 may be right, tho one size down may be ok at higher pressure

 

[EViS]

Thanks mike, would purchasing a HVLP gun be a wiser move? If so, would the tip also need to be around 1.8 mm?

 

[mike os]

not sure i am qualified to advise on that.. dont do enough.

hvlp at that size will need a fair sized compressor for anything more that a few bits.

I tend to make it up as I go along with spraying ( bit of experience helps)

I guess the place to start is what kit do you currently have & how much spraying do you have to do, or see in the future?

 

[EViS]

I don't have any kit at the moment. I started of thinking to go down the compressor route as it would come in useful for other things in the future where as a turbine-HVLP only has one use.

However, I'm really stumped at what precisely it is that I need for the task ahead. This is made up of 3x 2440x1220 MDF sheets which need a perfect eggshell-like finish.

 

[mike os]

Airless may be worth a look if you have no kit... Wagner do some small pumps that are OK & reasonably priced. http://www.wagnerspray.co.uk/

not tried mine on really thin materials though... paint that is... as I have both But suppoed to be good... I have the 117 & it does walls & ceilings like you would not believe.

 

[EViS]

I have looked at airless, however the kit is a tad more expensive and there is less control of how much paint is being applied.

There is no real reason for me to go with Dulux or F&B. Maybe I should go with a paint that has been designed to be sprayed. In which case, what paint manufacturers are recommended?

 

[jaykay]

dont use car paints ,as it will crack.mdf will expand, paint will not.
yes, i meant turbine set up.
you dont say what it is for.decorative??

 

[EViS]

When aluminium panels expand on cars (due to heat or dents), why does the paint not crack (not being a smart ass, genuine question)?

The panels are for decoration yes.

 

[jaykay]

can only tell you from exp.
metal does'nt expand that much.
get 3mtrs of timber,measure it. then stand the end in water and measure again a cpl of days later.bet it grows 15-20mm

 

[brightspark]

building interior humidity causes dimentional change in wood . metal does expand but no where near as much as wood

 

[EViS]

Didn't realise that MDF, based on the way it is manufactured, follows the same rules as cut timber.

 

[jaykay]

mdf,even more so.
is this a job,diy for yourself or what????

 

[EViS]

This is for myself as well as an education in paint technology.

 

[jaykay]

wickes do a mdf primer,thats not bad.
if it was me,i'd lay on 3-4 coats of that.flat it off when fully dry. then roller on topcoats.in the right hands you can get a good finish.
thats taking your using a emusion paint.

 

[EViS]

Thanks for the advice jaykay. However, the MDF boards aren't flat as they have been heavily routered to form patterns. Hence, roller'ing isn't an option. Since starting this thread and speaking to a couple of people, it's apparent that using emulsion is not the right way of going about things. Hence, I have now found 3 paint manufacturers who specialise in spray-paint for wood products . I now need to decide whether I opt for a waterborne, pre-cat or acid-cat paint...