Paint spec for renovated sash windows

[O'Chippy]

I have used sovereign solvent based wood preservative for years and it dries quickly and have never had a problem when overpainting it. So far in 40+ years I have not known anything rot after treating with sovereign wood preservative. If I make sash windows I would normally make a tray so I can submerge the lower part of the box window in the tray while I brush the preservative over the rest of the box. I do the same for the sashes then put sticks on top of the tray and stand the box sash on them so any surpulus drips back into the tray.

Regarding paint it does seem that: Tikkurila otex adhesion primer then valti ultra topcoat is popular. The top coat is supposed to be flexible and last between 8-12 years which is very good. I have used Santex in the past and generally obtain around 8 years before a re-coat is needed. But I might give the Tikkurila otex adhesion primer and valti ultra topcoat a try if I'm spraying or even brushing because it sounds very good.

Thanks for the response @meccarroll.
Good to hear your extensive experience of using wood preservative and how overpainting it has performed for you. I'll add sovereign to the list.

Yes the Tikkurila otex adhesion primer/valti ultra topcoat is popular.
I'm in the process of selecting a sprayer, the "pro-sumer" Graco A30 was the frontrunner however it cant handle solvent based paints (or anything with a flash point <100deg), therefore I'm also consider the Graco GF21 which is a professional machine but obviously more expensive.
I need to figure out if I can live without the need to use solvent based paints or if the upgrade is a wise selection.

 

[Doug71]

I tried the Bedec MSP and found it very thin, it needed multiple coats although this was in white and I think most modern white paints suffer from this. That was brushing on, not spraying though.

 

[deema]

I recently went through the same selection process of a an airless paint sprayer. I went down the Wagner route and selected the followimg
https://www.paintsprayer.co.uk/wagn...IzeQNasVW5phPF6W7HzoaetnbQt75VnkaAo2CEALw_wcB

It can spray both water and solvent based paint. I was lucky and picked up a secondhand unit for a fraction of the new price. May be worth taking a look. Wagner also own Titan, which has a lifetime warranty on the pump, ie it doesn’t wear out. The two units look almost identical, so I decided knowing a little about manufacturing that it would be highly likely that the same pump is within both units. Spares arnt too bad in a worst case scenario. The ‘big’ advantage from Greco appears to be that you can change the pump without tools. For me, if you don’t need to change the pump, that’s a much bigger advantage.

 

[deema]

I tried the Bedec MSP and found it very thin, it needed multiple coats although this was in white and I think most modern white paints suffer from this. That was brushing on, not spraying though.

A highly regarded and very knowledgeable architect who used to post on here highly recommended Bedec paint, if memory serves he used to state that it was the paint he specified for all external joinery.

 

[O'Chippy]

I recently went through the same selection process of a an airless paint sprayer. I went down the Wagner route and selected the followimg
https://www.paintsprayer.co.uk/wagn...IzeQNasVW5phPF6W7HzoaetnbQt75VnkaAo2CEALw_wcB

It can spray both water and solvent based paint. I was lucky and picked up a secondhand unit for a fraction of the new price. May be worth taking a look. Wagner also own Titan, which has a lifetime warranty on the pump, ie it doesn’t wear out. The two units look almost identical, so I decided knowing a little about manufacturing that it would be highly likely that the same pump is within both units. Spares arnt too bad in a worst case scenario. The ‘big’ advantage from Greco appears to be that you can change the pump without tools. For me, if you don’t need to change the pump, that’s a much bigger advantage.

I haven't looked at that particular sprayer but looks like a good option.
Interesting that it can spray solvent so I had a look if the wagner DIY machines can also spray solvents and it appears that they can.
That to me seems like a big advantage over the more expensive Graco A30

 

[deema]

I have to say, my first ‘have a go’ with airless was with a Screwfix Erbauer EAPS600 Electric Paint Sprayer 600W that costs c£200. It has both a primary and secondary filter and can take any of the standard nozzles from Wagner of Graco. It’s 200 bar pressure so the same as the premium brands. It comes with a 5 year warranty. Now, the pressure setting is a bit crude, but otherwise is lasted for around 150 litre of spraying before the pump started to give in. I got my money back and bought the Wagner. The point I’m making is that it’s the nozzle that determines the finish as long as you have sufficient pressure…..which this unit has. The finish it produced was excellent with the cheapest water based paint I could find that had the consistency or porridge and the nozzle it came with. It can spray solvent paint too.

 

[O'Chippy]

I have to say, my first ‘have a go’ with airless was with a Screwfix Erbauer EAPS600 Electric Paint Sprayer 600W that costs c£200. It has both a primary and secondary filter and can take any of the standard nozzles from Wagner of Graco. It’s 200 bar pressure so the same as the premium brands. It comes with a 5 year warranty. Now, the pressure setting is a bit crude, but otherwise is lasted for around 150 litre of spraying before the pump started to give in. I got my money back and bought the Wagner. The point I’m making is that it’s the nozzle that determines the finish as long as you have sufficient pressure…..which this unit has. The finish it produced was excellent with the cheapest water based paint I could find that had the consistency or porridge and the nozzle it came with. It can spray solvent paint too.

@deema Can you shed any light on what determines some sprayers rated to spray solvent based and other not so? My understanding is that it regards the sprayer's ability to safely run solvents with low flash points, something to do around with how the machine is grounded, if it is brushesless or not......
Its seems that there are oil based solvents with relatively higher flash points (which some diy machines can safely use) and there are true solvents with low flash points which general only the professional level machines can safely use.
Perhaps there is some fudging going on from the manufacturers claims regarding the ability of the diy machine?

 

[deema]

It’s just my opinion, and not to be taken as anything other. I believe for these types of machine the ability to spray solvent is to do with the materials used in the gun and feed tubes. It doesn’t relate to anti flash systems. Spray systems for highly volatile paints need a full anti flash room, lights, extraction fans, etc etc all have to be anti flash along with air fed respirators. For the typical useage of a mobile airless sprayer you won’t or shouldn’t be spraying highly volatile paints as you won’t be using it within a suitable environment.

 

[RobinBHM]

@deema Can you shed any light on what determines some sprayers rated to spray solvent based and other not so? My understanding is that it regards the sprayer's ability to safely run solvents with low flash points, something to do around with how the machine is grounded, if it is brushesless or not......
Its seems that there are oil based solvents with relatively higher flash points (which some diy machines can safely use) and there are true solvents with low flash points which general only the professional level machines can safely use.
Perhaps there is some fudging going on from the manufacturers claims regarding the ability of the diy machine?

I believe it also has something to do with the seals

 

[meccarroll]

It’s just my opinion, and not to be taken as anything other. I believe for these types of machine the ability to spray solvent is to do with the materials used in the gun and feed tubes. It doesn’t relate to anti flash systems. Spray systems for highly volatile paints need a full anti flash room, lights, extraction fans, etc etc all have to be anti flash along with air fed respirators. For the typical useage of a mobile airless sprayer you won’t or shouldn’t be spraying highly volatile paints as you won’t be using it within a suitable environment.

I have read that some paints that emit solvents can/may ignite if the right equipment is not used. But do correct me if I am wrong...I believe some none air feed PPE filters are capable effectively blocking solvents, gasses etc provided the concentration is not too high.

 

[deema]

It’s a few years ago I was involved in paint systems. Legislation may well have changed, and my memory may well have faded. But, my recollection is that in certain conditions, eg volatile car paint spraying positive air pressure masks are mandatory that are supplied from a location outside the spraying area. The reasoning I believe is that although there are mask / filters that can remove the contaminants the issue is that masks are not always fitted / fitting correctly allowing contaminated air to bypass the filter. Positive air pressure overcomes this issue which is why they are mandatory in certain circumstances.

 

[johnnyb]

I've sprayed msp but I found it a bit soft. I got a great gloss black finish but it's very easy to damage. I used a high build undercoat and coverstain primer. Otherwise the grain becomes really prominent. I've sprayed barn paint extensively and that is a good paint. Where you'll struggle is with build on old stuff. New stuff sanded to 120 these paints are great and hold up really well. Older stuff is tricky. Especially In winter. At least 13 degrees for one day needed for cure.
Ankerstuy is my goto for sprayed new work. The high build primer is outstanding. But I don't thin any of it having an AAA pump. When you you thin that water causes the wood grain issues, its much less with unthinned paint(although still there if you don't use coverstain)

 

[johnnyb]

The barn paint is just a single component system no primer undercoat Nada. Barn paint has more thickener added than msp. But with a pump system it doesn't matter how thick really.

 

[meccarroll]

It’s a few years ago I was involved in paint systems. Legislation may well have changed, and my memory may well have faded. But, my recollection is that in certain conditions, eg volatile car paint spraying positive air pressure masks are mandatory that are supplied from a location outside the spraying area. The reasoning I believe is that although there are mask / filters that can remove the contaminants the issue is that masks are not always fitted / fitting correctly allowing contaminated air to bypass the filter. Positive air pressure overcomes this issue which is why they are mandatory in certain circumstances.

Agreed if the air you receive is at a higher pressure than the spraying environment and clean air is supplied you shold be protected. PPE is a measure that needs careful consideration and not to be skipped over. Thank you for the reply.

 

[O'Chippy]

I've sprayed msp but I found it a bit soft. I got a great gloss black finish but it's very easy to damage. I used a high build undercoat and coverstain primer. Otherwise the grain becomes really prominent. I've sprayed barn paint extensively and that is a good paint. Where you'll struggle is with build on old stuff. New stuff sanded to 120 these paints are great and hold up really well. Older stuff is tricky. Especially In winter. At least 13 degrees for one day needed for cure.
Ankerstuy is my goto for sprayed new work. The high build primer is outstanding. But I don't thin any of it having an AAA pump. When you you thin that water causes the wood grain issues, its much less with unthinned paint(although still there if you don't use coverstain)

Thanks for feedback on MSP. Struggling to reach 13 degs this week at least, but perhaps I could cobble together some manner of drying spray room/area to keep the tempreture up.
I've seen the Barn paint online and sound like a better option than the MSP in this instance.

Ankerstuy seems like a premium option, their website isn't for the layman!
My windows are well sanded back, pretty much zero old paint remains. Ankerstuy seem to have two suits ranges. Can you say if I'm correct to assume their Hydrolux it the one to use?

 

[johnnyb]

Yes hydrolux is the acrylic top coat. The other is a superb paint but it's a water based pu lacquer really a solvent based lacquer but somehow in water.
The filler primer is great if you can spray it. Hydrolux top coat is about as thin as these things get.(they add thickeners for brush application also tannin block(to the primer) if you ask.)
It's a great product and not silly inexpensive per litre.

 

[johnnyb]

I would also stress that these paints are a system intended for new work. You would be unwise to discount traditional methods on old work ie face glazing the windows, dealing with knots ,cutting in, building end grain, curing all of which are addressed in different ways in a water based system. Traditional materials oakum, putty,knotting, oil paint(yes even linseed paint jacob) are super materials if you have time and patience to use them. BTW China bristle brushes are being phased out so get them while you can....

 

[O'Chippy]

I would also stress that these paints are a system intended for new work. You would be unwise to discount traditional methods on old work ie face glazing the windows, dealing with knots ,cutting in, building end grain, curing all of which are addressed in different ways in a water based system. Traditional materials oakum, putty,knotting, oil paint(yes even linseed paint jacob) are super materials if you have time and patience to use them. BTW China bristle brushes are being phased out so get them while you can....

Haha, I've actually discounted the old methods, hopefully not out of ignorance but a few other factors that swing the balance towards spraying.
I have been able to remove the box frames entirely, which I imagine will make spraying easier. Spraying is a skill I want to acquire, I have a good lot of work coming up which can be sprayed and these window now are a good opportunity to jump in at.
And speed. time pressure of getting the job done is a big factor; I'm a novice sprayer but I'm also novice painter and I think (rightly or wrongly) that spraying if not quicker won't be any slower than the brush.
Interestingly Mighton, (who do all things sash window-ish) seem to have some arrangement with Ankerstuy where they sell their paints under the Mighton brand.
I follow Bradshaw Joinery on Youtube, he did a sash window build series, he used the Mighton/Ankerstuy paint and sang it praises.

Perhaps a call to Ankerstuy UK to enquire about the suitability of there paint for my particular project may be wise.

UPDATE:
I called Ankerstuy, spoke to a very helpful guy there called Jason. He pointed my towards the Heritage Hall case studies project on their website and recommended the use of the products used there for my project.

 

[johnnyb]

Interestingly you've discounted linseed paint which is the darling of the sash window brigade. Unfortunately no use in the coming months.
I feel if your definitely going to spray water based you need an air assisted airless set up. Anything else won't cut it as the temperature drops the viscosity increases making hvlp pretty useless. Even 5 stage.

 

[Jake]

I don't think sash windows are a great subject for spraying. Lots of narrow pieces with big holes. And the paint ideally lips onto the glass over the seal which you can't realistically achieve.