Using dulux polyurethane clear gloss varnish

[gperkins1973]

Hi there,

I need some help.....

I have painted my subwoofer boxes which are made out of mdf a gloss black finish. Unfortunately this has had to be done by roller as I don't have a spray gun.

I applied 4 coats of primer followed by 3 coats of this gloss black paint wet sanding in between coats and also on the final coat.

http://www.screwfix.com/p/leyland-gloss ... tAodrhoADw

After the 3rd coat I purchased some of this:

http://www.travisperkins.co.uk/p/dulux- ... 58/3893395

I applied this with a gloss mini roller as the person in brewers advised me to but when it dried it had roller marks all over it.


I wet sanded this down and decided to paint another coat of gloss black over the top so now it looks alot better all be it not perfect.

I purchased one of these brushes because I thought it would be better to brush it on.

http://www.screwfix.com/p/hamilton-pres ... sh-3/48574

I am now unsure and worried about wet sanding down again or if I should just apply the gloss varnish straight over the top of the gloss black.

The boxes are quite big (24" wide by 48" high by 30" deep) so you see why I thought about rollering on the varnish. I did try a small area with a cheap brush but it left brush marks hence why I rollered.

I would really appreciate some advice as you can imagine how long it takes to wet sand these. I have two of these boxes to do.LOL.

I have attached a couple of pics. The orange peel effect has reduced quite a bit since the last wet sanding session.

regards

Graham

 

[deserter]

Why are you varnishing? Gloss paint will give a finish just as good as varnish and equally hard wearing.

For best results use liquid gloss, warm it up, by placing the can (opened) into a bowl of warm water, then apply it with a mohair mini roller.

Once you have it built up and it has had time to fully harden (this can take up to 2 weeks) wet sand through the grits until you reach at least 1500 grit.

Hope this is helpful.


~Nil carborundum illegitemi~

 

[gperkins1973]

Sorry I didn't realise that gloss paint would harden the same.

One my last wet sand I started off with 600 grit and then with 2000 grit paper to smooth.

Is it worth applying any more than 4 coats of gloss black paint or should that be enough.

It's not completely smooth. I have tried wet sanding as much as I can but all it does it remove the black paint even with 2000 grit paper.

What is the advantage of the mohair roller over a gloss one?

regards

Graham

 

[ColeyS1]

For years I hated finishing various projects I'd been making. Paint was paint (or so I thought) so i use to buy whatever was cheapest at the time. In my experience Leyland paint isn't the greatest. Get a tin of dulux and prepare to be amazed

 

[gperkins1973]

LOL it's a bit late for that as I have applied 5 coats of Leyland now.

To be honest the paint is pretty good. It's pretty thick and covers really well.

My only issue was not doing more prep work but on these size boxes it would take forever.

These things weigh a tonne and moving them around is hard enough. LOL.

I think the paint has made them heavier.

I have wet sanded down again with a combination of 600/1200 grit paper and have bought some mohair rollers so will see how I get on.

 

[Ian down london way]

I've always used a three coat approach. Normally, I'm doing boards (I did a dresser like this), so lots of the problems were about doing both sides, and tidying up edges.

1) coat with a non-drop brush.

LEAVE TO REALLY REALLY DRY

rub down with wet and dry paper (~ 1000 is ok). This will leave a matt finish. If you come across any nips (set drops) that haven'y set internally, you may need to let it dry again, and then resand those bits.

2) coat with a non-drop brush brush

Leave it to really dry (then leave it a bit longer!)

gently rub down with 0000 wire wool.
Honestly.
Make sure any bits of broken off wire are removed. You don't want any wet varnish being contaminated with wire wool - hence the need to really really let it dry.
This will again, leave a matt finish.

3) Last coat is applied using a pad made from non-fluffy fabric. You make a pad of cotton sheet or something like that, and wipe it on with the pad. You really are only applying a really thin skim coat, that fills in the very fine scratches from the wire wool. Its like french polishing, I think - must be videos of that, and how to make the rub for it.

Wait for it to dry

Admire.

DON'T DO ANY MORE RUB DOWNS.

 

[gperkins1973]

I have applied another coat with the mohair roller and it was loads better and smooth.

Open slight issue was that being a new roller, the first bit I did is covered in hairs.

Do I need to clearn the roller with water or white spirit before I use it.

I am going to have to wet sand the bit down and re paint.

I just want to make sure I don't get the hairs again. I have put the old one in white spirit as I was going to re use that in the morning.

 

[deserter]

First off sorry I didn't get chance to answer earlier, but you've found out why mohair is better now I assume.

I normally blast mine with the mrs's hair dryer to blow any loose hairs away and then the first roll or so I do onto a scrap of MDF to be sure, then I'm good to go.

As has been mentioned you can either leave your top coat un-sanded and use the gloss finish for the shine, or if you really want to wet sand it to a mirror finish you can polish it with a fine compound and a wool bonnet on an angle grinder or drill.


~Nil carborundum illegitemi~

 

[Phil Pascoe]

Even good quality brushes and rollers can drop hairs - the decorator I used to work with always washed his new stuff and dried it over night before first using it. If you intend to use brushes or rollers the next day you can wrap them well in clingfilm overnight.

 

[Ian down london way]

I've found that varnish moves so much, there isn't a problem with brush marks (although I do mine horizontally. So I use the non-drop brushes, there there is a block of plastic, and bristles are extruded from the block (not held in place by a band) - so there is no problem with dropping at all. They leave larger brush marks, but the vanish easily moves under gravity to loose the marks. I'd never use 'proper' bristle brushes for varnish.

 

[gperkins1973]

So would applying the polyurethane clear gloss varnish bring out shine more. To be honest if I see another sheet of wet/dry sand paper I am likely to go mad.

I did want the mirror finish and would have spent more time on them if they were much smaller or just hired a spray gun LOL.

Deserter, it is defo much better with the mohair for sure and looks smoother.

 

[carlb40]

So would applying the polyurethane clear gloss varnish bring out shine more. To be honest if I see another sheet of wet/dry sand paper I am likely to go mad.

I did want the mirror finish and would have spent more time on them if they were much smaller or just hired a spray gun LOL.

Deserter, it is defo much better with the mohair for sure and looks smoother.

What about a polishing compound, once the paint has fully cured? You would get a mirror polish on it then

 

[gperkins1973]

What do you mean apply the polishing compound straight on the gloss black paint.

 

[deserter]

Yep leave the gloss 2 weeks to fully harden, then use a polishing compound to remove the minute marks left by your 2000 grit paper.


~Nil carborundum illegitemi~

 

[gperkins1973]

Thanks mate will do that and let you know how I get on.

cheers

Graham

 

[Muswell]

When I was making speaker cabinets I just applied black paint with a roller. They were to be used in clubs so a reflective finish would not have been good and my client (aka son) and I liked the finish. However I have made a couple of guitars with black necks and it drove me mad because every little defect in preparation shows up, but it only really shows when you get towards the end. I finished using french polish because with that there are no brush marks. You can get the mirror finish which you see on grand pianos, but that is not so good for playing so I rubbed back slightly to take off the gloss. The first guitar was for someone else who wanted the effect you got on some old classical guitars. The second one was for myself and I did the black neck again because I felt there had to be a better way than the first time and was determined to find this. I don't claim any great expertise in this, just telling you what I did. I would not do it again....life is short.

 

[gperkins1973]

Yeah I know what you mean. I have just wet sanded with 2500 grit paper lightly and then applied some maguires polish as a test ( I am going to get some maguires ultimate compound shortly ) and it came up pretty shiny and smooth.

I have seen a vid of the maguires compund and it brought up some really dull paintwork so I am hoping this will bring it up really shiny and mark free.

I will upload some pics tomorrow to show how it looks.

cheers

Graham

 

[twothumbs]

I have just read through this rather late. Most interesting everyone. Advice I got from a paint company technical department was to use the best quality sleeve gloss roller in a large roller ie 9"+ to avoid any trail marks and avoid using a small roller which was my obvious first choice. It will cover the ground quickly but not so easy on edges , etc so a bit of thought required first but no reason to doubt it. Anyway....Best wishes to you all.

 

[rafezetter]

I'm curious to know how you got on with this finish - the polishing compound part.

On the occasions I've needed a good flat effect, I've painted as normal with roller or such to get colour; then wet sanded; then added a final coat heavily thinned and added an additive that increases the self levelling flow out of the paint. Always horizontally.

I also do the last coat with a sponge or cloth pad as mentioned by Ian down london way.