Water based paint, airless sprayer and orange peel

[Ikneweskimo]

I make fitted furniture, and whilst being experienced in the joinery side of things, I have just taken up spraying.

I've bought a graco ultra airless spray gun after using my friends HVLP system which seemed to struggle to keep up with amount of paint I needed to spray (think the compressor didn't have enough power)

I have been experiencing orange peel when spraying water based paints, namely Tikkurila Helmi. I have read loads of reviews about how good the paint is, and I didn't experience the problem when using it with the HVLP system. But when I spray it with my graco I'm getting an orange peel effect. It does settle quite a bit after drying but it's still there when viewed in certain lights/angels. I've tried making sure the paint isn't too cold. Standing further away when spraying, putting the gun on a low pressure, putting the gun on a high pressure and have run out of ideas now. Has anyone else experienced this issue? I did read watering it down may help but I spray MDF and worry what it would do in terms of grain raising . I know people spray water based with airless sprayers and get a good result, I just don't know what I'm doing wrong and it's getting quite demoralising now. Here are some pictures of the paint when first applied and after 16 hours dry time.


On a side note, do all airless prayers put out a ridiculous amount of paint? I changed to an fflp 212 tip to reduce over spray but the gun just eats paint.

 

[Inspector]

I'm not a finisher but have heard silicone spray lubricants or spray waxes with silicone can cause fish eye and orange peel problems. Any chance the gun or wood has had silicone of some kind on/in it? Years ago in my fathers repair and refinishing business they cursed Pledge and similar furniture waxes.

Pete

 

[jrm688]

With my Fuji HVLP spraying waterbased poly I had some orange peel problem at first. I figured that the poly was drying before it could "flow out". I found the solution was to keep the shop humidity above 50% RH when spraying. There is a "flow-tol" (maybe not spelled right) additive which is supposed to even the coating. I have seen silicone fish eyes on auto paint and they were circles where the paint was repelled by silicone. I think that has something to do with surface tension.

 

[TRITON]

What size needle ? Different size needles and spray caps for different viscosity of finish.
The thicker the finish, the thicker the needle.

So possibly a case of thinning the paint and using a thinner needle, or maybe just thinning it.
Have you a viscosity cup ?

 

[sometimewoodworker]

I have been experiencing orange peel when spraying water based paints, namely Tikkurila Helmi. I have read loads of reviews about how good the paint is, and I didn't experience the problem when using it with the HVLP system.

It’s perfectly possible that the paint isn’t the best fit for your spray system.
But, first step is check the Ford cup rating for that paint from that gun, adjust as needed, just guessing is a poor choice, and if using water based paint thinning by adding water will make no difference to MDF. Next check to see if Floetrol is OK and try using that. Also drop a question to @petermillard of the 10 minute workshop Fame as he has quite a bit of experience and probably had a similar difficulty or didn’t because his paint worked well with the gun.

FWIW I have never found that changing the tip and needle size to control paint volume was a good idea. YMMV.

 

[RobinBHM]

n experiencing orange peel when spraying water based paints

Airless spray systems have the power to atomise high viscosity materials at high flor rates. The problem is that if the viscosity of the surface coating is too high, the paint won't flow out and orange peel is the result.

Thinning the paint is the only solution. Be very careful, water based paint can't be thinned much, it's around 5% maximum. (Ask manufacturer)

I would try about 2% to start with.

 

[johnnyb]

try thinning a bit. I use an air assisted airless piston pump. same thing but with a bit of air to disperse the horns.( air powered though)
some airless pumps are a bit weak (small)and can struggle with fine finishes a bit. but orange peel is not enough flow after the spraying.
try a non water based primer(say bin) then thinning with a bit of water.
I get orange peel with leyland gloss as its like a jelly. shake the tins in the paint shop they should be liquid.im guessing the jelly effect is something that's added for a reason. try valspar v700 that was perfect(for my setup).

 

[petermillard]

I never had the problem spraying Helmi through an UltraMax, and I’ve never found the need to thin any Tikkurila paints or primers - they were always good to go, straight from the tub - and no need for additives like floetrol, in my experience.

What primer/undercoat are you using? Did that spray OK without orange peel? Did you denib after priming? Between topcoats? What’s the sheen level on what you’re spraying - Helmi 10, 30, 80? I used a 310 tip for pretty much everything, and the pump pressure typically around 3 on the dial. The only time I had orangepeel was either with the pump set too high, and/or spraying too close to the workpiece.

Might be worth checking the tip as well - mine came with a faulty tip fitted, which caused all kinds of overspray problems, and I didn’t know enough about it then, to know what was going on.

I’ve stopped spraying now, but the Graco handhelds do throw out a lot of paint; mine was fine - while it was working - for hose-piping large panels quickly, but terrible for any kind of finished piece, or smaller, sectioned workpiece. The pump fragility is an issue as well; Graco have never stated a duty cycle for the pump, claiming there were too many variables. When I bought mine folks were saying the pump was only good for 500 litres, and my pump died after 8 months and a lot less paint than that. Word ‘out there’ now is that they’re good for ~200 litres - which sounds more like what I put through my first one - but that makes for an interesting economic proposition, for a pump at £200 a pop.

I gave up on mine a year ago when it threw a wobble during my last commercial build; it resurrected itself enough to get the job finished, but flat refused to work at all when I lent it to a pal, which left him in a jam over a bank holiday weekend. If & when I ever get it back, I may pull it apart to see what’s what inside, but I wont be replacing the pump again. It’s a shame, as the system had such great promise, especially for one-man maker/installers who may only need to spray a wardrobe or two per month; unfortunately, these were exactly the situations that threw up issues with my Graco - using it occasionally, after it had been laid up for a week or three.

Not sure if any of this really helps, but that’s my take on it, for now. P

Edited to add: Be cautious about using anything but water-based paints in the Graco Ultra; my understanding was that the UltraMax was the machine to use for anything flammable, as the brushless motor won’t spark.

 

[johnnyb]

is a 212 tip quite big. I think the numbers mean( I did a course with titan over 10 years ago) 2 thou tip with a 12 inch fan. if that's right no wonder it chucks paint out.

 

[johnnyb]

Peters tip at 310 is a more sensible fan the 3 thou hole will be because the machine is a bit gutless. a decent airless can have a smaller tip hole

 

[johnnyb]

sorry some misinformation there. a 310 tip is 30 degree spray angle with a 10 thou tip. 212 is 20 degree with 12 thou tip. the smallest I could see was 209.
sorry

 

[Ikneweskimo]

I never had the problem spraying Helmi through an UltraMax, and I’ve never found the need to thin any Tikkurila paints or primers - they were always good to go, straight from the tub - and no need for additives like floetrol, in my experience.

What primer/undercoat are you using? Did that spray OK without orange peel? Did you denib after priming? Between topcoats? What’s the sheen level on what you’re spraying - Helmi 10, 30, 80? I used a 310 tip for pretty much everything, and the pump pressure typically around 3 on the dial. The only time I had orangepeel was either with the pump set too high, and/or spraying too close to the workpiece.

Might be worth checking the tip as well - mine came with a faulty tip fitted, which caused all kinds of overspray problems, and I didn’t know enough about it then, to know what was going on.

I’ve stopped spraying now, but the Graco handhelds do throw out a lot of paint; mine was fine - while it was working - for hose-piping large panels quickly, but terrible for any kind of finished piece, or smaller, sectioned workpiece. The pump fragility is an issue as well; Graco have never stated a duty cycle for the pump, claiming there were too many variables. When I bought mine folks were saying the pump was only good for 500 litres, and my pump died after 8 months and a lot less paint than that. Word ‘out there’ now is that they’re good for ~200 litres - which sounds more like what I put through my first one - but that makes for an interesting economic proposition, for a pump at £200 a pop.

I gave up on mine a year ago when it threw a wobble during my last commercial build; it resurrected itself enough to get the job finished, but flat refused to work at all when I lent it to a pal, which left him in a jam over a bank holiday weekend. If & when I ever get it back, I may pull it apart to see what’s what inside, but I wont be replacing the pump again. It’s a shame, as the system had such great promise, especially for one-man maker/installers who may only need to spray a wardrobe or two per month; unfortunately, these were exactly the situations that threw up issues with my Graco - using it occasionally, after it had been laid up for a week or three.

Not sure if any of this really helps, but that’s my take on it, for now. P

Edited to add: Be cautious about using anything but water-based paints in the Graco Ultra; my understanding was that the UltraMax was the machine to use for anything flammable, as the brushless motor won’t spark.

Hi Peter,

Thanks for your response.

To be honest I watched your 'playing at spraying' playlist and decided to buy the Graco after because it seemed ideal for what I would use it for! The Helmi products come recommended by quite a few makers I follow on Instagram too and they seemed great when I was using a really cheap hvlp gun.

I've been using the Helmi primer, sanding the grain raising, then applying second primer. It didn't seem to orange peel with just primer but I'll.double check as I still have some peices that need a top coat.

I've now run out of paint as the gun used so much - a whole 2.7 litre tin for 3 small doors and 4 100mm plinths which seems ridiculous. Especially at £50 a tin!

Could you tell me how the tip was fitted incorrectly? I had a 310 but changed that and the seals to the 210 (not 212, oops) to reduce overspray when spraying the edges of 18mm doors. But it doesn't seem to have made any difference.


I'll turn the power down, I has it quite high as I read the paint needed to be atomised more to avoid my issues, but maybe that's made it worse.

 

[petermillard]

Hi Peter,

Thanks for your response.

To be honest I watched your 'playing at spraying' playlist and decided to buy the Graco after because it seemed ideal for what I would use it for! The Helmi products come recommended by quite a few makers I follow on Instagram too and they seemed great when I was using a really cheap hvlp gun.

I've been using the Helmi primer, sanding the grain raising, then applying second primer. It didn't seem to orange peel with just primer but I'll.double check as I still have some peices that need a top coat.

I've now run out of paint as the gun used so much - a whole 2.7 litre tin for 3 small doors and 4 100mm plinths which seems ridiculous. Especially at £50 a tin!

Could you tell me how the tip was fitted incorrectly? I had a 310 but changed that and the seals to the 210 (not 212, oops) to reduce overspray when spraying the edges of 18mm doors. But it doesn't seem to have made any difference.


I'll turn the power down, I has it quite high as I read the paint needed to be atomised more to avoid my issues, but maybe that's made it worse.

No problem. Yes, and be fair my Graco absolutely did the job that I bought it for, but longer-term I'm afraid it's not worked out well at all, and I have talked about the issues in other videos - most recently the 'my last build' series (playlist here). There will be another follow-on vid about this, but I need to get the gun back, before I can make it. On mine the supplied tip wasn't seating properly against the little rubber seal, so it was getting a lot of paint blowing around it; I didn't realise this (new to spraying, new to airless) and it caused all kinds of issues that a simple replacement tip resolved. But that was the 'gotcha' about the whole thing for me, really - the ultra 'system' looked so good on paper for occasional users, and the flex liners are pure genius, but the times when it played up the most were exactly the situations that I bought it for - when I picked it up to use after a few weeks of being laid up.

You probably know this already, but a 210 tip will only change the size of the fan, not the amount of paint it puts out. An x08 tip will reduce the paint flow, but this can cause other issues, especially with more viscous paints like the primers. Also, one thing I have discovered the hard way is that spraying is a skill that you have to learn, like any other, and we tend to expect instant, perfect results - because it's 'just painting' right? - whereas if we looked at it with a slightly different perspective, the orange-peel you're getting on those doors for example, is probably less than the roller-rash you'd get from using a foam roller. You expect it to be better than that, of course - this is spraying, it should be, and can be better - but it does take practice to achieve those results, too.

Let us know how you get on.

Peter

 

[johnnyb]

I would say don't be to disheartened if your first goes aren't like glass. you will find each stage adds to the overall effect. nearly all paint can appear slightly orangey when its wet. you are looking for this to flow out over the next few minutes. temp and humidity play a much more prevalent role with water base product. when my gun is set right I hardly have any overspray( as there's only a bit of air to blow it around)I do end up with a slippy floor after a good session..

 

[sometimewoodworker]

one thing I have discovered the hard way is that spraying is a skill that you have to learn, like any other, and we tend to expect instant, perfect results - because it's 'just painting' right? -

Very true. That is something that many people overlook. It is also a skill that needs to be practiced at reasonably frequent intervals to keep current, leave it for too long and you will forget somethings, DAMHIKT,
Probably air spraying is more difficult to get correct as there are more variables and 3 of them are (or can be) varied on the gun while using it
tip & needle size
Air pressure
fan width
Finish volume
finish flow rate (dilution).
distance from workpiece
angle and speed of movement of the gun

with that airless there is (as I understand it) only 1 variable on the gun

 

[JonOuk]

Short answer- paints too thick probably
Experiment with thinning by water usually 5-10% and make sure to flatten all the under coats properly.
Also check your running the correct pressures recommended for the finish (could be too low)

 

[gog64]

Hold on a second. Am I the only person who thinks: “2.7 litre tin for 3 small doors and 4 100mm plinths” and the OP getting orange peel might be connected? I’ve just sprayed 8 doors, 4 drawer fronts, 2 side panels, about 3m of plinth and some trim with 1 litre. 2 coats all round plus a third on the face. And I’ve got a bit left.

OP - you mention that it’s laying it on thick. You have adjusted the paint flow right down haven’t you? If so, I’d be contacting the vendor for advice.

 

[sometimewoodworker]

Hold on a second. Am I the only person who thinks: “2.7 litre tin for 3 small doors and 4 100mm plinths” and the OP getting orange peel might be connected? I’ve just sprayed 8 doors, 4 drawer fronts, 2 side panels, about 3m of plinth and some trim with 1 litre. 2 coats all round plus a third on the face. And I’ve got a bit left.

I agree on the connection. But did you spray airless?

I am getting similar coverage both with shellac (though I do try to flood that a bit as I’m probably spraying around a ½lb cut) and a water based polyurethane. But then I’m spraying with air not airless and I don’t have airless equipment so it’s difficult to get enough polyurethane flowing to put on too much as it’s building up on the spray tip quite quickly. That the problem of spraying when the temperature is over about 30C to 35C

I would probably say that it’s inexperience. I didn’t dream of spraying a project before doing enough practice to get my technique at least passable. Something that may well be useful that hasn’t been mentioned yet is a film thickness gauge, they are cheap enough and will certainly show if the paint is going on too thick

 

[gog64]

I just went & checked & as usual I was far too optimistic. I actually used about 1.8l (Johnstone’s acrylic durable eggshell). I still think the 2.7l the OP used is very heavy though.

BTW a figure of 5% max water dilution was mentioned. Johnstones instructions say 10% and I’ve found 5-10% works OK for me on HVLP.

 

[Ollie78]

Don`t have the same spray equipment so cant help there exactly. If this happens to me I find it is because i am laying it on too thick, or it is drying too fast and can`t flow out.
The temperature and airflow of the booth could be an issue, as said before try thinning it just a tiny bit.

This is why a good old toxic solvent based acid cat laquer can`t be beaten. I have gone water based and while less toxic etc I am finding it just not quite as good a finish.

Ollie