Welcome To Ask The Trades!

Quote: Always forgive your enemies; nothing annoys them so much - Oscar Wilde
  HomeHelpSearchLoginRegisterPM to admin  
 
Page Index Toggle Pages: 1
Send Topic Print
[Advice] Spray Painting MDF (compress + gun) (Read 10023 times)
wozzer
Junior Member
**
Offline

The Jurassic Spark
Posts: 58
Total Thanks: 0
For This Post: 0


Gender: male



Re: [Advice] Spray Painting MDF (compress + gun)
Reply #15 - Mar 31st, 2016, 2:47pm
 
Just a comment - I have custom built several radiator covers and these were roller-painted with a white satinwood finish.
I found that getting the paint on fairly quickly and evenly then finishing off with slow roll over using just the weight of the foam roller gave a very respectable finish...If it helps!
Back to top
 
Thank User For This Post View members image gallery  
IP Logged
 
woodsmith
Global Moderator
Trade Member
Author
*****
Offline


Posts: 4164
Total Thanks: 78
For This Post: 0


Gender: male

Trade: Joiner

Re: [Advice] Spray Painting MDF (compress + gun)
Reply #14 - Sep 8th, 2013, 9:11am
 
You can use wet and dry paper (wet) as long as you make sure you don't go through the finish and wet the MDF.

If you are now going to roll it I would get some Floetrol paint additive and mix it in with the paint. It makes the paint flow out more and helps reduce roller marks.

If your base layers are not completely flat then spraying the final coat will not give you a perfect finish, I'd try the Foetrol and see how you go on with that.

My first gun snapped where the quick fit connector was screwed on, when you look at them you get a lot of high tolerance parts for little money so the quality has to be suspect. I now have a DeVilbis trans tech HVLP gun which cost about £300 but its light years better than the cheap guns. I also have a small belt driven compressor, I can't remember how much I paid for it but it wasn't too expensive and it works well and is reasonably quiet. If you are returning your kit that would be something I would recommend you looking out for next time.
Back to top
« Last Edit: Sep 8th, 2013, 9:12am by woodsmith »  
Thank User For This Post WWW View members image gallery  
IP Logged
 
elso
Junior Member
**
Offline

Ask The Trades
Posts: 8
Total Thanks: 0
For This Post: 0



Re: [Advice] Spray Painting MDF (compress + gun)
Reply #13 - Sep 8th, 2013, 12:04am
 
Many Thanks for the advice! Unfortunately as I was securing the hose to the the valve of air tap, this broke in two parts...
pretty bad, I will return the compressor, it won't hopefully be a problem. So I am trying to do all the job with rollers and sanding in between coats.
The grey water based primer (Morrells) was pretty good, the top coat lacquer you recommended is very good too, although I can't seem to be able to hide the strokes left by the rollers. Feels a bit bad, with all the expectations I have built in preparation for the compressor...
Can I wetsand the mdf in between coats? And also is it possible to achieve a good result with rollers only? or should I top the lacquer with an automotive can?
Back to top
 
Thank User For This Post  
IP Logged
 
woodsmith
Global Moderator
Trade Member
Author
*****
Offline


Posts: 4164
Total Thanks: 78
For This Post: 0


Gender: male

Trade: Joiner

Re: [Advice] Spray Painting MDF (compress + gun)
Reply #12 - Sep 7th, 2013, 7:57am
 
I think there are a couple of problems using a compressor that is under powered for the gun, firstly the pressure will drop as you spray and affect the finish. This may not be too big a problem but worth looking out for. Secondly if, as you have found, the compressor runs continuously it will not have a long life, they are designed to cycle and have chance to cool off. You can probably get around this by spraying for a couple of minutes and then waiting a few minutes before starting again.

Getting a bigger compressor would be expensive and then you would want a better gun so even more money! I'd give your set up a go and just be aware of its limitations.
Back to top
 
Thank User For This Post WWW View members image gallery  
IP Logged
 
elso
Junior Member
**
Offline

Ask The Trades
Posts: 8
Total Thanks: 0
For This Post: 0



Re: [Advice] Spray Painting MDF (compress + gun)
Reply #11 - Sep 7th, 2013, 12:06am
 
Just a silly thought, just when I was about to start painting with the spraygun I happened to be talking to the technical department from Sealey, they told me that if I use a compressor with a bigger gun, I risk blowing the compressor and damaging it beyond repair and that I should simply buy a bigger compressor.
I thought that in a similar situation I would only have to wait for the compressor to replenish the air container every few minutes, I didn't think I was gonna burn the compressor itself.
What do you think? Sorry for all these questions, first time not using aerosol cans and would like to get this right.
The compressor is  http://www.tool-net.co.uk/p-366874/sealey-sac5030ve.html?gclid=COSPyZzvt7kCFe_Lt... and the Sealey gun is http://www.ebay.co.uk/itm/S701G-SEALEY-PROFESSIONAL-GOLD-AIR-GRAVITY-FEED-FED-PA... I know that as a rule of thumb a compressor should have 1+1/2 times the value of the cfm required by the gun.I tried it briefly today and nothing was wrong, except that the compressor was running continuously.
Many thanks for your help

Best
E
Back to top
 
Thank User For This Post  
IP Logged
 
elso
Junior Member
**
Offline

Ask The Trades
Posts: 8
Total Thanks: 0
For This Post: 0



Re: [Advice] Spray Painting MDF (compress + gun)
Reply #10 - Sep 4th, 2013, 12:20am
 
Thank you so much!
Buying it now!
Back to top
 
Thank User For This Post  
IP Logged
 
woodsmith
Global Moderator
Trade Member
Author
*****
Offline


Posts: 4164
Total Thanks: 78
For This Post: 0


Gender: male

Trade: Joiner

Re: [Advice] Spray Painting MDF (compress + gun)
Reply #9 - Sep 3rd, 2013, 4:33pm
 
Look at Morrells 10% sheen black water  based lacquer part no 8106/318 if you want a really matt finish.

http://www.morrells.co.uk/products/wood/3
Back to top
 
Thank User For This Post WWW View members image gallery  
IP Logged
 
elso
Junior Member
**
Offline

Ask The Trades
Posts: 8
Total Thanks: 0
For This Post: 0



Re: [Advice] Spray Painting MDF (compress + gun)
Reply #8 - Sep 3rd, 2013, 3:00pm
 
Okay then,
sorry for delay, compressor and gun arrived today, will treat the MDF with 2 pack bondo for now and try to achieve a decent finish.
Meanwhile I just bought the Flat MDF primer and will see how it goes, I am still thinking about spraying it if possible. Will send updates.
Also, I am still up for a black matt (or non gloss) finish, any specific paint I should use? Many thanks for all your suggestions, will send some images  Smiley
Back to top
 
Thank User For This Post  
IP Logged
 
woodsmith
Global Moderator
Trade Member
Author
*****
Offline


Posts: 4164
Total Thanks: 78
For This Post: 0


Gender: male

Trade: Joiner

Re: [Advice] Spray Painting MDF (compress + gun)
Reply #7 - Aug 31st, 2013, 3:37pm
 
Other than Toolstation for MDF primer I get most of my paint from Bromborough Paint as they have a shop relatively nearby, but I think they only have outlets on the northwest. Morrells and Technos are two good makes of paint you could Google.

If you prime with a roller you will find it very hard to get a perfect finish. I would normally spray the primer too. One thing to watch is that the MDF will soak up the primer, resist the temptation to keep applying paint or you will soak the board. Give it a decent coat then let it dry before applying another coat (probably undercoat). Another thing to watch is that the MDF primer will not give a good opaque layer unless you have put it on too thick. Just put enough primer on to do its job then use the undercoat to give you a good opaque coat.
Back to top
 
Thank User For This Post WWW View members image gallery  
IP Logged
 
elso
Junior Member
**
Offline

Ask The Trades
Posts: 8
Total Thanks: 0
For This Post: 0



Re: [Advice] Spray Painting MDF (compress + gun)
Reply #6 - Aug 31st, 2013, 2:28pm
 
Great, thanks!
After considering I would have needed 300£ worth aerosols, I ended up buying a 3hp Sealey compressor and a sealey gun with two sets 1.4 and 2mm for the same price. They will arrive on Tuesday.
Meanwhile can I ask you where you buy the paint from?
Thanks for the advice re the MDF, I though about buying the moisture resistant from Travis Perkins, this time I am with the normal one, it doesn't look too cheap though, there are some minor details to be fixed with some 2 parts bondo and then I will be ready to spray.
Do you recommend using MDF primer with a roll?
Yes I am aware that every imperfection will show up if not take care, that's why I was thinking about spraying primer...
Thanks for your help!

E
Back to top
 
Thank User For This Post  
IP Logged
 
woodsmith
Global Moderator
Trade Member
Author
*****
Offline


Posts: 4164
Total Thanks: 78
For This Post: 1


Gender: male

Trade: Joiner

Re: [Advice] Spray Painting MDF (compress + gun)
Reply #5 - Aug 30th, 2013, 7:27am
 
MDF should need very little sanding on the face, it's the edges which are the problem as it can be a furry mess on some types of MDF. I find moisture resistant boards to be better and never use ordinary MDF any more. So I don't think you will need a powered sander, just a cork block and some fine grit abrasive. I use Mirka as it doesn't get clogged with finish.

Matt black easily becomes polished with use but most top coats would spoil a completely matt finish. Generally the more matt it is the less durable it is. I have used Polyvine decorators acrylic varnish (its called dead flat) and that seems to be a good compromise between finish and durability.
Back to top
 
Thank User For This Post WWW View members image gallery  
IP Logged
 
elso
Junior Member
**
Offline

Ask The Trades
Posts: 8
Total Thanks: 0
For This Post: 0



Re: [Advice] Spray Painting MDF (compress + gun)
Reply #4 - Aug 30th, 2013, 1:24am
 
Thanks a lot.
I had a look at the undercoat products from Rustoleum and they don't look too bad. Thanks for the advice.
There are a few videos where ppl have been spraying Rustoleum with a compressor, and they used small ones like the Craftsman Professional  27 Gallon Vertical Portable Air Compressor.
I thought it could be a good idea to spray it with the compressor i order to save time and achieve a good result.
Regarding the sanding tools, I have access to some festool orbital one.
Should I also layer some protective/clear coat on top? I am doing matte Black.
Back to top
 
Thank User For This Post  
IP Logged
 
woodsmith
Global Moderator
Trade Member
Author
*****
Offline


Posts: 4164
Total Thanks: 78
For This Post: 0


Gender: male

Trade: Joiner

Re: [Advice] Spray Painting MDF (compress + gun)
Reply #3 - Aug 29th, 2013, 2:04pm
 
I use Flag MDF primer from Toolstation; seems to be good and not too expensive.

I am currently using Glidden water based primer undercoat but they all seem pretty similar.

One thing to bear in mind is that water based paints are thicker than solvent versions and are therefore more difficult to spray. You can't thin them down a lot or they will lose adhesion.

If I was going to use a brand of finish paint, like Rustoleum, I would play safe and use their undercoat too.

The only slight problem is that if you brush or roll, which would be better, the primer on, you need to get that surface as close to perfect as possible as any marks will show through the final finish.
Back to top
 
Thank User For This Post WWW View members image gallery  
IP Logged
 
elso
Junior Member
**
Offline

Ask The Trades
Posts: 8
Total Thanks: 0
For This Post: 0



Re: [Advice] Spray Painting MDF (compress + gun)
Reply #2 - Aug 29th, 2013, 10:11am
 
Thanks for the suggestions!
Do you use water baser primer too?
Re the undercoat: if I use aerosol (was thinking about Rust-oleum) for the top coat, what type of undercoat paint should I use?
The idea of the car body shop is a very good one indeed, it is merely a question of time at the moment, as I will have to have everything done by the 5th/6th of Sept at the latest.
Best wishes

Elso
Smiley
Back to top
 
Thank User For This Post  
IP Logged
 
woodsmith
Global Moderator
Trade Member
Author
*****
Offline


Posts: 4164
Total Thanks: 78
For This Post: 1


Gender: male

Trade: Joiner

Re: [Advice] Spray Painting MDF (compress + gun)
Reply #1 - Aug 29th, 2013, 8:23am
 
To get a compressor and gun to spray effectively would be pretty expensive. I would think it more cost effective to use aerosols. Another option though would be to take them to a car body shop and they could spray them for you. For a less perfect finish you could even use small foam rollers.

As for finishing MDF I fill any gaps with a 2 pack filler, give all the end grain a coat of MDF primer, sand this down then give the entire job a coat of MDF primer. This is then coated with 2 coats of undercoat which is sanded down with fine wet and dry abrasive (not too wet) before giving it a couple of top coats. I use all water based paints as I don't have the facilities for 2pack or the like and the finish is very good IMHO.
Back to top
« Last Edit: Aug 29th, 2013, 8:24am by woodsmith »  
Thank User For This Post WWW View members image gallery  
IP Logged
 
elso
Junior Member
**
Offline

Ask The Trades
Posts: 8
Total Thanks: 0
For This Post: 0



[Advice] Spray Painting MDF (compress + gun)
Aug 29th, 2013, 1:24am
 
Hi There,
I am a newbie when it comes to painting, I had experience of painting Car Body Filler on resin before with decent results and using aerosol spray primer and paint, but I was thinking about moving to a compressor this time.

I need to paint 5 boxes (about 1.5mt x 50cm x 10cm each) for an artwork I am preparing; they will have to be painted Black, Matte.
The MDF will be sealed with PVC glue and water and then levelled with some car body filler.

My questions are:
- As I cannot use 2pack (don't have a respirator nor a big garage where to spray or extractor), what type of paint should I use? And where should I buy it from?

- Will I be able to spray primer and paint with a compressor, such as this one i.e.?
Quality Portable V-Twin Pump Compressor, Sealey SAC5030VE (50 Litre, 3hp, 11.6cfm Displacement)
would this be enough for this type of job or should I buy a smaller/bigger one?

- Gun.... any suggestion?

Despite I would like this job to be made nicely, I don't plan to use the compressor too often in the future, or to go pro, hence I should go for a smaller?

I am also considering doing everything with aerosols, it's just that I feel it'd be much easier with the compressor.

What do you think?

I read some of the comments on the forum, but I am still confused wether or not I should go for compressor or paint it with a brush or aerosol

Many thanks in advance for your help and time


Best

Elso

Back to top
 
Thank User For This Post  
IP Logged
 
Page Index Toggle Pages: 1
Send Topic Print