# Dulux Eggshell problem (now solved) then MDF painting tips



## RobertMP (22 Nov 2008)

_29.11 Changed the thread title as there is some general info on MDF painting on page 2 now._

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Bit of an essay... sorry.

I'm trying to spray a lot of MDF that I've turned into parts for refreshing our kitchen with new doors and trims as you may have seen 
here in my WIP thread.

I thought I'd identified the problem I have been having with bits appearing in the finish coat of Dulux Trade Eggshell..... but now I'm not so sure.

There are some pictures in the other thread.

What happens is that the eggshell coat spontaneously develops 'dust' within a minute of being applied to the door panel - and a few 'fish eye' spots.

I spray the coat on and it is wet and even with *no* inclusions and as i stand there looking for problems they appear across the panel at random positions.

I've been doing some tests to try and work out what is happening and I'm getting more confused!

so far..

1, I stretched a plastic bag over a piece of chipboard so I had a guaranteed clean virgin surface and spray painted the bag with the eggshell. Perfect - no dust. no fish eyes. left it to dry - still perfect.

2, All doors etc are painted and rubbed down with a water based MDF primer made by Leyland paints. This was what I thought was the problem and reacting with the topcoat. Bought some oil based undercoat. undercoat shows only slight reaction. today I sprayed eggshell over the oil based undercoat... and got the same reaction 

3, Tried spraying the paint neat but the gun won't have it. Bought some expensive high purity white spirit 'for thinning paint' (been using wickes stuff) and thinned by the minimum to get it to spray - same problem.

4, Tried wiping down with white spirit, meths, and even cellulose thinners in an effort to stop fish eyes. cellulose seems to reduce it a bit but is too aggressive on the primer.

5, tried not rubbing down an undercoated panel at all - same reaction. tried not wiping with anything on a sanded primed panel - same reaction.

6, I had a small amount of Leyland paints Eggshell so I tried that instead of the Dulux - it reacted slightly less but still reacted in the same way.

So I'm a bit lost as to what to try next. painting plastic proves the paint is clean and can stay clean. painting anything with a previous coat on it (even recoating sanded eggshell) just looks dirty.

Any suggestions gratefully recieved!


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## Chris Knight (22 Nov 2008)

Robert,
You must be very frustrated by now! I am sorry I don't have a solution for you. Normally a "dusty' finish is the result of not getting a proper wet coat on the job but you have all but eliminated this in your comments and by the results on the plastic.

I'd still be inclined to question the drying time but my first instinct would be to turn to Dulux for the answer. 

Not many folk on this forum seem to use sprays so you might get a better answer elsewhere. I'd recommend a couple of American sites except that Dulux is presumably a UK brand people might not know. This is Jeff Jewitt's site/forum and he has been helpful to me in the past but I don't know how your query may be dealt with - worth a go though.
http://www.homesteadfinishing.com/phpBB2/


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## jasonB (22 Nov 2008)

How are you removing the dust from the rubbed down surfaces, a tack rag will remove far more than just wiping with a duster. If there is dust on the surface before you spray it will come to the surface as the solvent evaporates and the film becomes thinner. 

Jason


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## wizer (22 Nov 2008)

Can you make your own tack cloths? It is just a rag with white spirit impregnated?


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## jasonB (22 Nov 2008)

You probably can, its stockinette but it has a more oily texture, don't know what it is.

Jason


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## RATWOOD (22 Nov 2008)

HI Robert
might sound funny but how long do you leave your extractor on before and after you finish spraying


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## JonnyD (22 Nov 2008)

I usually hoover the surface with a soft brush vacumn attachment gets it really clean. 

The fish eyes you describe are usually a sign of contaminationon the surface with something such as silicone. 

I use a paper disposable filter to make sure the paint is clean and free of bits. Temperature can also make a difference i try to spray at a miminmum of 15 degrees but its not always easy to get the workshop warm enough.

jon


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## RobertMP (22 Nov 2008)

In no particular order..

I have used tack rags (starchem branded) as I first thought it was dust. I've even wiped half a panel with the tack cloth and left half un wiped - no difference.

I've been filtering the paint with disposable fine filters and there is a filter on the suction tube of the gun.

The extractor stays on while I watch the spots appear. Temperature was something I wondered about. I have some heat in the workshop but obviously it all goes out the wall once I turn on the plate fan.

Dulux and Leyland eggshell paints both have the problem so it is not unique to dulux.

There is no dust on the workpiece or in the paint. 'dust' miraculously appears up through the paint - I can watch a lovely smooth wet surface turn spotty!

I could just carry on and paint everything, as if you are not looking as closely as I now am you probably wouldn't see the faults. Knowing that the paint can go on perfect (as spraying a poly bag proved) it is frustrating to have to consider something less.

Many years ago I've sprayed lots of stove enamel and I've even sprayed a car but I've not come across a mystery like this one. Spraying wood and HVLP are the new factors I don't have huge experience of. Fish eye spots that don't respond fully to thorough pre cleaning is another new one.


Thanks for the input.


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## RobertMP (22 Nov 2008)

I got an air tools kit included with the compressor I bought a year or so back. Think I'll find the included ultra low quality spray gun tomorrow and try some conventional high pressure spraying as tomorrows experiment. Not that I really expect it to prove anything....


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## jasonB (22 Nov 2008)

Another possible is that by sanding back the primer you are exposing any raised fibres which could then be swelling as the solvent soaks into them. I would suggest applying the primer to a non absorbant surface such as a scrap of MFC or laminate, rub down as per your doors then eggshell. If no problem then we can rule out the primer not being compatible with the eggshell.

Jason


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## Shrubby (22 Nov 2008)

Robert
Very frustrating when this happens near the end of a good project!
Jason sounds right - have you flatted back the primer too much? or need a second coat to allow for sanding to a super smoth finish.
The only thing i can add is the fan.This will pull dusty workshop air across the workpiece.I worked in a tiny place with a similar setup to yours, we sectioned off a corner with clean air drawn in through a window to supply the booth fan
Matt


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## RobertMP (22 Nov 2008)

Think I have ruled that out. It happens on the dulux undercoat and when applying a second coat over eggshell that has dried and had the nibs knocked off. new spots appear in plain previously good areas not necessarily on top of old ones.

Can't get my head round it being fine on a plastic surface and not fine on a painted one... whatever it is painted with.

Still worth double checking. I'll try a second coat of undercoat and not rub it down, even if there are any spots, before putting eggshell over it just to see if the sanding is opening pores that suck dry spots in the paint... or something. Hmm sucking the solvent out and leaving piled up paint solids does sound like a theory. Plastic is not porous :idea:


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## jasonB (23 Nov 2008)

BTW Dulux do not recommend spraying their oil based eggshell!! though that may be more a H&S issue than practical.

Jason


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## RobertMP (23 Nov 2008)

It does say health and safety as the reason on the tin. I'm wearing a carbon cartridge filter mask and cant even smell the paint plus the plate extractor is pulling it all away from me so I'm not too worried.

I've been out for a look at the few drawer faces I sprayed yesterday. Most of the 'dust' eruptions have vanished again! That was not happening when spraying onto the MDF primer so the dulux undercoat must have helped even if it did not look like it when wet.

I can still see the fish eyes but I doubt anyone else would notice them. I will experiment a bit more but it does look like I have a way forward after all.


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## RobertMP (23 Nov 2008)

Today I've sprayed a fresh coat of Dulux undercoat onto the 8 panels and trims for the first area of kitchen I want to complete.

With them done I dug out this cheapo spray gun and wished I'd cleaned it after spraying preserver on the shed with it last year :lol:

Anyway it cleaned up OK so I put some Dulux eggshell in it - poured unfiltered from the paint I had previously had in the Fuji Q3's gun. I sprayed 2 drawer faces with it. Both had previous coats of the same paint which I had rubbed down to flatten the odd spot and some prominent fish eyes.

There were no new fish eyes using the paint with the high pressure cheapo gun. I could see the slight impression of the ones I had rubbed the top off of but no new ones appeared. Now I'm not going to condemn the Fuji HVLP just on the evidence of 2 panels but it has made me think. The 'dust' after spraying has happened just the same but hopefully they will reduce with drying like I saw last time.

The Fuji was an excellent condition used unit - does anyone know if there is something inside it that could age and cause contamination of the air? looks like more testing tomorrow to try to pin down the source of the contamination. It would explain why I couldn't wipe the panel clean enough to stop it though.


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## CNC Paul (23 Nov 2008)

Robert,

It sounds like the wrong tip/nozzle size in the Fuji. Where you thinning the
Dulux in the Fuji ?


Paul


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## RobertMP (23 Nov 2008)

Yes. Thinned to about 35 seconds originally. With the new high purity white spirit I added just enough to some fresh paint to get it to spray but have not checked the viscosity on what was only the one cup full of mixture (though it is thicker).

The Fuji has the original (#4?) 1.4 nozzle kit. Guess I could invest the £40 in a 1.8 (?) set. Also wondering if the intake filter should be changed.

Thinking tomorrow I will try spraying half a panel with air only from the Fuji then spray the complete panel with paint using the high pressure gun and look for fish eyes again.


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## RobertMP (24 Nov 2008)

Well I've solved the riddle of the fish eye spots.

I have taken out the intake filter on the fuji Q3 and it was dusty. So I took off the end box assembly with the sound deadening inside and blasted everything with compressed air. Put the end back on but left the filter out.

Tried a test spray - still making fisheyes 

So I unscrewed the hose connector near the gun held a bit of stocking material from a pair of the mrs old tights over the thread and screwed it back together as a inline filter. Fisheyes still happening but less than half what there was before and mostly small ones.

I did let the fuji run for a while with nothing on the hose end but either the contamination is not coming from the filter or there is so much in the system it will keep coming through.

I have a sheet of hard plastic that I can spray then wipe off and spray again for testing. Sprayed it 3 times with the fuji and 3 times got fisheyes appearing. Sprayed it twice with the el cheapo gun on my small compressor and no fisheyes at all.

I do think the 'bits' in the paint are mostly drying symptoms now and arguably fit in with the notion of 'eggshell'

Not sure now there is much to be done with the fuji apart from selling it on ebay


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## Jake (24 Nov 2008)

One differences is the higher temp of the air through the gun with the HVLP, which a paint not designed for spraying might not like.


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## RobertMP (24 Nov 2008)

I've just managed to spray a panel with the Q3 without fisheyes 

I took the hose off the turbine unit and left it running while I beat the cabinet about a bit with a bit of rubber and specks landed on the white cloth I had in front of it .... then I screwed a garden hose connector on the front and attached the only bit of plastic pipe I had which is only 4ft long. So with the unit on a stool behind me i tried it out - no fisheyes and less 'dirt' than before too.

It appears resisting the temptation to throw it out the window was not such a bad idea.

I don't trust the fuji hose to be clean so I'll get a bit of garden hose for now.

Hopefully I can make some progress soon.


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## RobertMP (24 Nov 2008)

With the garden hose fitted I am finally producing a spray finish I am happy with 

Thanks for the suggestions and sympathy. You may have helped keep me sane though all this :lol:

All seems so easy now.


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## Chippyjoe (24 Nov 2008)

Hi there,new to this forum but find it very interesting always good to hear other opinions.
Robert sorry to hear about your problems with your Fuji.
I have just finished a refit of my stepsons bedroom with built in units etc all made out of MDF. In the past I have made units etc out of MDF and hand painted them which is where I felt let down as to the finish.
I tried everything to try and achieve a professional finish but never got there!!!
So this time I decided to invest in a Fuji Pro4 system,at the moment it still sits in the box unused,after reading the problems that you have had I am wondering whether I should return it while I can get a full refund ! Would be interested to know if you solve your problem,and if anyone else out there has sprayed MDF with a HVLP system succesfully?


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## RobertMP (24 Nov 2008)

Welcome to the forum.

I'm spraying it pretty good now 

If I do sell the Q3 on ebay when I'm finished I will buy another (new this time) next time I need to spray. Think I'd go for the Q4 too as a little more pressure would be nice.

I think something has happened to sponge intake air filter and it has contaminated the whole air path through the unit including the hose with minute specks that repel paint when they find their way into the applied film. There seems to something about eggshell paint that causes the reaction as the primer and most of the undercoat went on fine.

Now that I have shaken any loose debris from the turbine and changed the hose it is performing beautifully and has restored my faith in HVLP.

I still don't like the fan control on the fuji gun and am using it with no fan but apart from that it is a good system now.

I have bought some aquarium air line valves and tubing to replace the fuji pot pressurising pipes and they work well and cost only 35p each (the valves are easy to accidentally ruin with paint getting into the pipe)


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## CNC Paul (24 Nov 2008)

Robert,

Did you buy the Fuji from new or is it second hand ? 

Spraying eggshell is extremely messy, why not try some pre-cat lacquer 10% sheen which is pretty near eggshell, plus it dries so much quicker.

Paul


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## RobertMP (24 Nov 2008)

2nd hand.

Think I'll persevere with the eggshell. Now I have the baffling problems solved it actually does not take that long to get a decent finish.

Also not sure where I'd buy something like that. Can't see my local trade decorators centre having it on the shelf.


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## Chippyjoe (25 Nov 2008)

Robert, glad you got your paint problems sorted. I was wondering if you could give me any tips on spraying with the Fuji? 
I am going to use a HVLP for the first time,having never sprayed before. 
I am going to spray eggshell (um!) onto mdf,I realise that I will have to seal the mdf first with a proper sealer and pay attention to the raw edges which I read somewhere you can do with drywall filler. 
The bit I need help with is,what kind of primer to use and how much do you have to thin the paint? 
Any help and any further tips from anyone, would be most welcome. 
Regards, Mark.

_________________
My partner doesnt understand my power tool fetish!!!


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## CNC Paul (25 Nov 2008)

RobertMP":3b4tnylp said:


> 2nd hand.
> 
> Think I'll persevere with the eggshell. Now I have the baffling problems solved it actually does not take that long to get a decent finish.
> 
> Also not sure where I'd buy something like that. Can't see my local trade decorators centre having it on the shelf.



Morrells supply all wood finishes ( Welyn Garden City and North London)




Chippyjoe":3b4tnylp said:


> Robert, glad you got your paint problems sorted. I was wondering if you could give me any tips on spraying with the Fuji?
> I am going to use a HVLP for the first time,having never sprayed before.
> I am going to spray eggshell (um!) onto mdf,I realise that I will have to seal the mdf first with a proper sealer and pay attention to the raw edges which I read somewhere you can do with drywall filler.
> The bit I need help with is,what kind of primer to use and how much do you have to thin the paint?
> ...




I get excellent results using Dulux oil based primer mixed with Dulux eggshell 2 parts primer 2 parts eggshell 1 part white spirit as a primer and then 2 coats of eggshell. I know it sound a strange combination but I have used it for years on kitchens etc without any problems. It works even better if you are using dark colours.



Paul


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## RobertMP (25 Nov 2008)

I'll give you a run down on what I did a bit later.

I will say though that if I do this again I will use an oil based primer as the water based mdf primer seems to stay too porous.


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## RobertMP (25 Nov 2008)

Tips based on my experience so far (which is this one job and a test piece I did before the project)....

Use the green moisture resistant MDF not ordinary. MR because the edges cut cleaner and sand up much easier not because of moisture resistance. I don't know what drywall filler is - I just sprayed it with primer.

You need a primer to penetrate the fibres and seal the surface and enough thickness so that when you rub it down you still have sealed surface left. I used Leyland MDF primer because it worked well on the sample I made and painted. When it came to recoat it I found it to be a bit too absorbent and caused little mounds of paint solid that looked a bit like dust spots. These spots mostly levelled out on drying. As said above next time I'd try an oil based primer. To get over the absorbant primer I am giving my doors 1 coat of Dulux trade undercoat before the eggshell.

The fuji can spray paint that is fairly thick and like brushed paint the texture from spraying thick does flow out level. Thick paint does not want to spray so it does need some thinning. I use the seconds cup to measure the viscosity. The primer was thinned with water to about 35 seconds and the top coat thinned with white spirit to slightly less - about 33. It is easier to get a good finish when the paint is thinned correctly. The right amount of thinning is when it sprays well but still has enough body to cover. Don't take my numbers as being right for you. You need a lot less thinner to go from 40 seconds to 35 than you do when the paint is thicker so be careful when the mixture is near to how you want it.

Thinned paint or primer does not seem to stay well mixed when left unused. I have a lidded plastic 5l container that I mix in and return any unused paint to it from the gun and give the pot another mix with a paint stirrer on a battery drill before starting work. i don't clean the gun - just refill it with freshly stirred paint.

Get some fine disposable paint filters and whenever you fill the gun strain the paint into the cup. I got 50 from ebay seller 'hugspaints' and they seem fine.

If you have never sprayed before spend a few days practising first. I have sprayed before but not HVLP so I painted all the cupboard doors in my workshop as a learning job. Getting an evenly applied WET film without sags or runs (from putting too much on) is what you are aiming for.

Make some jigs to make life easier with handling and access. I made a turntable and some stands and they have been great.

Spraying Oil based you need a good mask. I use a half mask respirator with a carbon filled 'organics' cartridge filter and can't even smell the paint. Pinch your nose after spraying oil based - any stickyness and your mask isn't working right.

Technique is down to practice and being methodical. Getting into a routine means you always end up with 4 edges painted and not 3.

Have plenty of old T shirt type rag handy and thinner for cleaning.

If you do completely screw up a panel you can always put some solvent on a rag and wipe all the wet paint off.

Dried paint around the gun nozzle comes off easy with cellulose thinners as used with car paints but don't let it near anything else 

The gun has a top suspension point so have something with a hook sticking out handy so you can put it down without danger of it falling over.

Tack cloths are good but not essential. Having a dust free surface is essential. I have some cloths so I use them but a dry hand and air blown from the gun is pretty efficient at shifting dust plus you get to feel any imperfections.

Don't use any hand creams or barrier creams as your fingerprints may cause problems then.

Edited after thought tips..

Start spraying with the paint flow knob screwed in so there is next to no paint coming out. then unscrew until you get a flow you can cope with. If it is still difficult to control try reducing the air flow slightly with a tap in the air line.

Light - you need to be able to see what you are doing. Spraying say white onto white is hard to see. Wet paint reflects so if you have light arranged to reflect off the work piece at you, you can see what is painted and what isn't.

I'm off for another days paint spraying. If i think of anything else I'll add it


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## Richard Findley (25 Nov 2008)

Hi guys,

Been following this thread with interest as I do a fair bit of spraying but am still on something of a learning curve.

If it is of any help to anyone, Morrells, who I get my waterbourne finishes from has a PDF with a troubleshooting guide here:

http://www.morrells.co.uk/downloads/TROUBLESHOOTING_GUIDE.pdf

HTH,

Richard


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## RobertMP (25 Nov 2008)

Just read through that. I knew most of it aready. It didn't mention crumbling intake air filter sponge on a HVLP turbine 

I can laugh about it now


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## GCR (26 Nov 2008)

Robert, many thanks for taking the time to record your experiences. 

Bob


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## Chippyjoe (26 Nov 2008)

Robert, thankyou for your advice and tips they make good reading.
There has been some times when I wished that I hadn't purchased the Fuji(and its not got out of the box yet!)and just painted the units with a hand brush but I guess it will be worth it in the end.
So I guess it will soon be time to grab the bull by the horns and go for it,thanks again.

Paul,thanks for your input as well.Being totally ignorant on paint as I am,would I be correct in saying that you do not mix an oil based primer with a water based eggshell? I realise that in the real world the two do not mix but is this the same with paint? please excuse my ignorance.

Richard,thanks for the information on the Morrells website will give it a look.

Thanks again guys, 
Regards, Mark.


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## RobertMP (26 Nov 2008)

Oil and water generally don't mix 

Spraying can be quite straightforward. I've just put the final coat on the first 3rd of the parts for my kitchen refit. took about 2 hours.

My recoat routine is to lightly rub the face with 600 wet and dry (used dry) to knock off any nibs but be careful not to break through on edges and corners - takes 30 seconds or so. If I've handled the panel a lot then a quick wipe with white spirit on a cloth. On to my stand for spraying. blow with compressed air. Quick light wipe with tack cloth. Turn it over and spray the back. Turn it over holding it by the edges. Spray the edges. Spray the face. move stand with panel somewhere to dry.


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## OLD (26 Nov 2008)

RobertMP In the past i have found the art of spraying and the gathering of information about it very difficult to come by. I have asked here for info and got only general stuff, this thread has been very helpful and you have been very open and i thank you very much, I think if i had your problems it would have really got to me but you have solved them and we benefit thanks again.


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## RobertMP (26 Nov 2008)

You are welcome. Just explaining my problem helped me find a way to the answer.

Being a bit impatient I just fitted a 300 wall unit door panel to a wall cupboard end (as a trim panel) even though the paint is not fully cured. I chose the door with the most evidence of past troubles still showing in critical light - and it looks perfect in situ! So I'm well pleased at how this is going to turn out. I'll add to my WIP thread with pictures once the rest is installed tomorrow.


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## RobertMP (19 Dec 2008)

In this thread there was a question about cleaning up time after spraying.

As I had to clean my gun today I thought I would take some pictures as I did it. taking the pictures took longer than the actual cleaning so overall it was a little over 20 minutes so 10 or less without the camera 

Before I start there was a question about overspray. The carpet scrap I stand on has been there all the time whist applying 4 coats to a complete kitchen worth of MDF and is pretty clean considering.






The gun isn't that bad really as I cleaned it thoroughly before changing to black.





Pull the trigger (no air connected) and let the paint in the tube etc drain out





Empty the pot





Splash of white spirit in the pot, fit to the gun and shake for a while.





Spray paint and thinner mix into a rag. max flow and no fan. Repeat with more thinner. I'm using a eggcup full as a rough amount.





The gun and cup afterwards.





Little bit of white spirit in a bottle bottom taken from the recycling box.





old toothbrush and a small bottle brush to clean the cap unit and the cup rim.





I stuff clean rag into the cup and twist to clean the inside





Dry paint on the outside I'll get off later





Air cap off. It has dry paint on it.





needle out





Dipped the brush in the white spirit and cleaned the gun insides. Either blast it through with compressed air or stuff some t shirt rag in to clean it after this.





Now the answer to the dried paint - cellulose thinners.





Very small amount in another bottle bottom and put the air cap in to soak.





While the dry paint softens I put a bit of cellulose thinners on a rag and clean the outside of the cup.





So there it is all clean and not much waste thinners. I pour them onto the rag I used to catch the spray and put it in the bin.





One other thing. The main cup was what I used for the bulk of the spraying. By the time I had finished there was a lot of dried paint on the outside. i put about an eggcup full of cellulose thinners into a plastic bag then put the cup in.





Closed the bag round it and left it for 30 minutes. When I came back the paint just wiped off.


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## Chippyjoe (19 Dec 2008)

Robert,that was very informative and helpful. So after all your problems ,was the end result as good as you hoped for? And are we going to see any pictures of the finished job?
I have yet to get my Fuji out of the box,still trying to locate an extractor fan at a reasonable cost!
Thanks again for all your help and tips.

Mark.


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## RobertMP (19 Dec 2008)

Its all in this thread . You can skip to the end for the finished pictures 

And yes I am pleased with the results


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## imaginarynumber (24 May 2009)

Hi all

Just a couple of points re spraying with eggshell.

1. As you are aware the air coming out of the gun gets quite hot- to reduce this problem you can buy another hose and effectively double the length. The other advantage of this is that you can now put the turbine in another room. My Fuji is one of the older noisier units so this is a boon- it also reduces the stress on the filter. 

2. Do use white spirit but reduce the amount and supplement with Owatrol oil (an expensive mix of turps and linseed oil). Owatrol is pretty much the same oil you find on the top of the paint when it have been left standing for a long time. Owatrol reduces the drying time slightly, allowing a longer working window. It also "lubricates" the paint without thinning it.

3. Clean the gun by spraying white spirit, then empty and pour in Dulux Trade brush cleaner and renovator (I have only ever seen this is 2.5l cans in Dulux Decorator Centres- previously known as MacDougal Rose). Then flush the gun by spraying with clean water. If necessary you can leave the parts sitting in the cleaner for a week or too.

4.ALWAYS strain your paint, even if a brand new tin. You can also use small filters that sit in the gun's cup on the feed pipe.

Water based primers and oil based top coats are fine together. I have only experienced fish eyes when having used shellac as the base and not ensured that the surface was dust free.

I tend to spray with two pack acid cat (from morrell http://www.morrells.co.uk/products/wood/4 ).

No grain swell with the primer- gorgeous to sand back and you can dictate the level of sheen on the finish coat. The biggest plus is the drying time (minutes before you can handle). Down side- very toxic- smelly- risk of combustion and cost- offset by convenience though.

Overall it is much easier to get a pro finish with the acid cat and your hvlp will find it much easier to atomise it. If you do have areas of dry spray you can polish them out.

DO NOT SPRAY WITH OIL BASED PRIMERS!!! - I once made the mistake of spraying a walk-in wardrobe with oil based primer and ended up in a cloud of sticky mist. The paint took ages to dry sufficiently to sand.


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