HVLP spraying of MDF / Poplar - primer?

[Wouldchuk]

Morning all,

I recently acquired an Earlex HV5000 model HVLP sprayer as I wanted to see if it was an improvement on brush... mainly in speed, but also comparable if not better results.

I have some shelves and cupboards to paint - MDF and Poplar faceframes.

Does anyone have any advice on the best primer / undercoat I can use? I was thinking about a bog-standard water-based primer from Screwfix or some such. They'll then need to be finished with an eggshell finish, ideally oil-based if I can find it.

Any advice much appreciated.

 

[oakfield]

I used to use normal primer/undercoat but found I had to thin it way past the manufactures recommendation to get it to spray.
I have since moved on to Morrells and I find it a great product, (most of the time...)

 

[Wouldchuk]

Hi Oakfield - which one do you use? I spoke to a chap at Morrells in High Wycombe and he spoke about a "pre-cat primer" - when i look online they do two sorts in the water-bourne range.

There's a high-solids white, which in the description it references use on MDF, or there is a White Anycoat Primer

And do you find it is ready to spray - no need for any thinning at all?

Thanks

 

[oakfield]

I use the 501 primer, which is the 'anycoat' one.
I had a chat to them about this only last week as I was wondering if I should try the 641 - high build one.
Apparently the 501 is a newer product and what most people are buying from them now.

I still put a splash of water in, maybe 10 - 20% maximum, but I'm sure you could spray it out the tin with the right equipment.

 

[Wouldchuk]

That's great - thanks - I'm going to order a tin and see how I get on.

Thanks for your help

 

[DaveyWills]

I have managed to spray MDF with several types of water based finish. Even value b&q primer. Before working on the finished piece I spray onto scrap wood and test it in small batches of paint with varying amounts of thinning, making a note of the ratio each time. When I find the right ratio, I go for it with the real thing.

Adding a small amount of Floetrol paint conditioner seems to help too.

Overall though it's a real pain getting everything dialled in correctly with the sprayer and cleaning the gun out every time is time consuming. I've come close to the same level of finish using a foam roller on mdf.

Good luck

 

[Wouldchuk]

Thanks Davey - I feared as much! I do have two sets of alcove shelves and another set of full height shelves to do so was thinking that the messing about getting things right would be worth it when there is that much to do still....even if only the primer.

 

[MikeJhn]

I use Morrells high build primer on MDF simply because of the amount of de-nibbing required, Its used straight from the can in a Fuji gun with a number 1.4 needle, IMO a roller will not get into those areas between raised panels and will need brushing out with the inevitable brush marks, not so much of a problem on an area that needs de-nibbing, but a big problem on the finish coat.

The Earlex that I used was the constant bleed gun, air coming out of the gun constantly picks up dust in the workshop which is always deposited on what you are working on.

Mike

 

[Stocksy27]

we use a sayer lack cellulose primer, quick drying and won't fluff mdf up like water base sands really good and flat too

 

[furnman]

I have also just started to use a cellulose high build pre cat primer by sayer lack which is distributed by "movac" here in the uk, I get through about 30 ltrs a month and i use a apollo HVLP set up which works well. I have used the morrells before but I did not think much of that. Mylands is also very good and only changed to the saylac due to cost and supply problems. I don't think much of water based products and will never use them. Cellulose rules for me and is great on MDF specially on the edges.

 

[MikeJhn]

Good to know the alternatives out there, will have to give the Sayer Lack a try.

One question do you have to dilute the cellulose high build pre cat primer? if so what size needle do you use? I suppose that's two questions. #-o

Mike

 

[MikeJhn]

Found the tech sheets on the Saylack: http://www.movac.co.uk/wood-finishes/in ... -coatings/ all I need to do now is find somewhere to buy it in Kent, a search on Google gave no results.

Mike

 

[furnman]

Hi Mike, yes you do have to dilute down as its very high solids, you will notice how heavy the tin is, you will need to mix the tine with a stick as all the solids sink to the bottom. It depends on your spray equipment but i normally do about a third, may be abit less than that. Its very fast with building up a finish on MDF. I am in east sussex and they do next day free delivery, just ring up the nearest depot at movac. If you have no joy pm me and will send you the south east reps name.

 

[MikeJhn]

Thanks for the info furnman, will give movac a call and see what they can do for me, if I don't get any joy I will PM you.

Mike

 

[ComfortablyNumb]

Movac will sort you out