A 'how to' for High Gloss Finishing

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diyAudio Member
Joined 2004
Re: Wagner or Spray Cans?

peterphan said:
First off, thanks to ShinOBIWAN and the other posters for their insights and advice. I'm inspired.

I want to finish a pair of homemade DECWARE High Definition Towers in glossy black, like ShinOBIWAN's original post. I don't have a HVLP gun nor air compressor, and can't justify buying either for a one-time project. A friend owns a Wagner hand-held spray painter, which I know is far from professional. As I understand it, the Wagner doesn't allow any fine tuning to control the atomization or pressure. Which would you recommend: using spray cans or the Wagner?

I'm not sure, I'd maybe lean towards the Wagner. The main advantage is that you can use quality automotive paints rather than the inferior stuff that comes in most cans. I suspect the Wagner will lay down more paint in consistent fashion too but you'll probably have to a good practice with it first.
 
diyAudio Member
Joined 2004
If your spraying MDF then you need a good few coats a primer (10+) with sanding every few coats. Then just a couple of the black basecoat to ensure coverage and then around 10 coats of clearcoat so you've got a nice thick gloss layer to work with when sanding and rubbing out.

There's quite a bit info I passed onto a friend, I'll dig it and post it since its fairly detailed.
 
ShinOBIWAN said:
If your spraying MDF then you need a good few coats a primer (10+) with sanding every few coats. Then just a couple of the black basecoat to ensure coverage and then around 10 coats of clearcoat so you've got a nice thick gloss layer to work with when sanding and rubbing out.

There's quite a bit info I passed onto a friend, I'll dig it and post it since its fairly detailed.

I use Zinser sanding sealer. It's an alcohol based sealer so you can clean out the spray gun with denatured alcohol. I tried to use the Turbinaire "ProCoat" Sanding Sealer on my most recent project, but every can of the stuff we opened (at the dealer) was "polymerized". Turbinaire makes a sprayable nice pore filler.
 
Re: Wagner or Spray Cans?

peterphan said:
First off, thanks to ShinOBIWAN and the other posters for their insights and advice. I'm inspired.

I want to finish a pair of homemade DECWARE High Definition Towers in glossy black, like ShinOBIWAN's original post. I don't have a HVLP gun nor air compressor, and can't justify buying either for a one-time project. A friend owns a Wagner hand-held spray painter, which I know is far from professional. As I understand it, the Wagner doesn't allow any fine tuning to control the atomization or pressure. Which would you recommend: using spray cans or the Wagner?

You might look at

http://www.prevalspraygun.com/

I've never used one, but the lady at the store where I buy my automotive paints says she sells a loy of them.
 
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Joined 2004
jackinnj said:


I use Zinser sanding sealer. It's an alcohol based sealer so you can clean out the spray gun with denatured alcohol. I tried to use the Turbinaire "ProCoat" Sanding Sealer on my most recent project, but every can of the stuff we opened (at the dealer) was "polymerized". Turbinaire makes a sprayable nice pore filler.

Yep, I do something similar:

I see that many folks, including myself are frustrated by the fact that MDF has an annoying tendancy to expand and spoil, be it with veneered or more severly with sprayed and painted finishes.

Some folks have suggested PVA/water mixes, shellac, level filling, resins etc.

I've tried most and still get the expansion to a greater or lesser degree but finally I have found something that truely works.

Its actually used for stabilising rotting wood and uses the moisture within the wood to actually form a chemical bond that looks the fibres in a resin cast that penetrates into the MDF. Once set its water proof and very tough, much tougher than untreated MDF, which also means I'd suggest you do all you sanding and detail work before applying this as it will cause you some extra work. Its excellent for applying spray finishes onto though as its almost like steel in its substrate toughness.

The one that I used is Bonda Wood Hardener:

http://www.decoratingdirect.co.uk/viewprod/b/BONWH/

I'd also highly recommend using void free plywood, its better than MDF by far for jointing and for absolute troublefree finishing use the wood hardener on this also.

Hope this helps folks out there, who like me, probably pull their hair out when they try to spray cabinets when faced with this problem.

Which is from this thread: http://www.diyaudio.com/forums/showthread.php?s=&threadid=60652&highlight=
 
Just a few thoughts.

I've had and used a Wagner gun for years. You can buy lacquer spray tips for them; finer hole, I think.

I've sprayed some car panels, color + clear, and although you get a bit of orange peel, to tell you the truth, I've seen more on brand new cars! You just need to wet sand and compund the surface well.

Regarding using many coats of clear. I'd worry about that. I've heard that since clear has no binders in it (?), it can be prone to breakdown if too many coats are used. Someone may be bale to confirm this. I mean long term.

Also, practice! It took me ages to learn how to hold the gun at a consistent angle and start and stop past the edges of the work. Also, make sure you have a clean gun & work piece and your lacquer is mixed perfectly. A warm day is also a must.

Mos
 
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Joined 2004
Mos Fetish said:
Regarding using many coats of clear. I'd worry about that. I've heard that since clear has no binders in it (?), it can be prone to breakdown if too many coats are used. Someone may be bale to confirm this. I mean long term.

I'm not sure what you mean by breakdown. I assume you mean peeling, flaking or something similar?

I've never heard that one but maybe its true for certain products and on certain materials, if you use a system of paints that are made for building up multiple coats as confirmed by the manufacturer then you should be able to avoid that but I've never seen, read or heard about that before so not sure how much a concern it should be.

One thing I have noticed with 1k clearcoat is that it takes forever to harden with a lot of coats - 1 month+. I switched to 2k exactly because of that and it passes the finger nail test after 7 days.

Another thing to note is you only get a really deep finish by using a thick clearcoat layer.
 
Someone mentioned Wagner I think..... don't. They don't atomize they just spit, and they don't spit consistantly due to running off their own pump they have a non consistant air stream. I wouldnt' waste automotive paint in it. You actually can find some decent spray bomb paints, Krylon actually gives a nice finish, the trick is to lay it on thick enough so that it flows.

As per thick layering of clear, key words were paint system. Don't mix brands or types and it should all stay put in the long term. Letting each coat cure a little more between coats can help drying time, or adjusting the level of thinner.

Alot of those layers get cut down while color sanding so you're not actually left with ten coats. It's also a good idea because it helps build a thicker layer around corners and the like, where it has a tendency to be a little thinner and could more easily be sanded right off, which you don't want to have happen.
 
diyAudio Member
Joined 2004
I wouldn't advise spraying, thinners have no effect on this stuff and when you come to cleaning your gun you'll have a hell of a time and possibly wreck it. My advice is to not spray resins but simply brush on and then throw the brush away rather than an expensive spray gun.
 
I wouldn't "hit a dog in the derriere" with a Wagner sprayer. Invest in a decent compressor and HVLP sprayer -- will save a lot of grief.

FWIW I have had a change of heart with respect to the Zinser -- completely took it off and went back down to the bare MDF -- used the DuPont 3 component Centari and its associated primer which we can get for the airplanes.

It's so humid, however, that I have had to bring the cabinets indoors. I don't know when we will get to the final finishing steps.

An externally hosted image should be here but it was not working when we last tested it.
 
jackinnj said:
I wouldn't "hit a dog in the derriere" with a Wagner sprayer. Invest in a decent compressor and HVLP sprayer -- will save a lot of grief.

FWIW I have had a change of heart with respect to the Zinser -- completely took it off and went back down to the bare MDF -- used the DuPont 3 component Centari and its associated primer which we can get for the airplanes.

It's so humid, however, that I have had to bring the cabinets indoors. I don't know when we will get to the final finishing steps.

An externally hosted image should be here but it was not working when we last tested it.

Could you, please, tell us what is the minimal (technical data) good sprayer (air compressor and spray gun) to act in good conditions?

Marc
 
My son uses a Husky sprayer which is pretty commonplace. We also have a 5 horsepower compressor. Make sure that you get a moisture trap on the compressor line. I had a Wagner -- they are OK to spray latex on the house or on a fence, but (in my opinion) aren't up to the task of dealing with a lacquer. I would conjecture that they might be dangerous with something which uses a volatile organic solvent.

There are much sexier and more expensive HVLP sprayers, but we get by with the Husky --

We also use the compressor to get the barbecue goin' "real good" you can get the charcoal so hot that it would be possible to melt the bottom out of the Weber.
 
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Joined 2004
Vikash said:
The label on the Wickes stuff says to clean up with cellulose thinners so I assumed it would be straight forward to clean up.

The advantage if it worked is that you wouldn't have to sand down a very tough surface before moving onto primer.

That'll be OK by the sounds of it.

The Bonda stuff isn't touched by thinners though. I tried cleaning out a paint brush with allsorts and it wouldn't budge. In the end it turned the bristles to rock and I threw it in the bin.
 
Hi everyone,

Finally my boxes are painted. Prep+sanding+primer+sealer+2 coats black+4coats lacquer -
all done in a amateur body shop garage. Any hope to achieve black piano finish? I am so afraid to go with sandpaper or rubbing compound over the present finish...

Thanks
 

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read the comment about spraycans and orange peel, and im feeling a bit proud actually, I did the bonnet of my golf mk2 with cans, and the front is peel free, i actually achieved a mirror shine the whole front throughout.
then ofcource i was beginning to run out of paint ^^

so the rest aint so smooth by a long shot, but if you use high quality boxes, then getting an awesome shine isnt that hard, i didnt have to sand at all, just went straight for the polish, and it is smooth.

offcource the boxes set me back 90 punds, half of what my 50l, 320l\m set me back, hehe.
im so looking forward to putting my new speakers in the paintbooth.

oh and offcource, thanks for another great sticky!
 
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