[Garbz]

I've got 2 projects on the way and I'm researching the best way to get a lovely gloss finish on both of them. We are talking almost pianogloss type finish, so really shiny.

The Pine is standard shelving pine so it's untreated and very porus. I was actually thinking of staining it black, and then glossing it.

The MDF is .. MDF. Last time i tried to do something like spraypaint MDF after sanding I was left with many little fibers hanging off so not ideal.

Anyone want to share som glossing tips?

 

[MASantos]

Quote:

Originally Posted by Garbz I've got 2 projects on the way and I'm researching the best way to get a lovely gloss finish on both of them. We are talking almost pianogloss type finish, so really shiny. The Pine is standard shelving pine so it's untreated and very porus. I was actually thinking of staining it black, and then glossing it. The MDF is .. MDF. Last time i tried to do something like spraypaint MDF after sanding I was left with many little fibers hanging off so not ideal. Anyone want to share som glossing tips?

Regarding the pine, you must use a product that "isolates" and "closes" the porus before varnishing. I don't know the english name for it but if you ask in your local home depot(or similar) they'll know waht it is. After that it must be sanded with some fine sand paper. I usually use 240 grit at this stage.
There are some varnishes that are specific for glossy finishes, so search for it. Another technique is to use regular varnish. YOu must apply the 1st and 2nd layer with very little varnish and let it rest for a night. THen use lots of varnish for the 3rd and 4th layers. The 4th layer should be applied as soon as the 3rd one doesn't hold to your finger.( about 20-30 mins.)

let it rest for one night and sand it with 400 or 800 grit varnish sand paper. Finally apply some wood oil like cedar oil or a similar product. I got this result using the above technique.
http://www6.head-fi.org/forums/showp...postcount=1164

 

[Qsilver2001]

For MBF you want its natural colour with just glossy finishing?
Or black glossy finishing on MBF board?

 

[Voodoochile]

Shellac or laquer or sanding sealer work well (I have used 'Deft'). But you do want to test compatibility of a sealer with the final coating to make sure it will not attack it.

Your idea of staining it first is good I think. That way inthe unfortunate event of a ding, at least it will still look dark, rather that light.

Wetsanding with 600 grit paper makes almost everything look beautiful!

 

[Francis_Vaughan]

There are many mixtures of materials that can be used successfully. I would tend to say that the common element in any really good finish is sanding. You simply can't get away without careful sanding between coats. That and a fanatical devotion to cleanliness. Keeping the area really clean and managing dust is crucial.

Sanding sealer is often prescribed to fill the pores in open grained wood. You can use it, but in truth you can get away without, but you will end up applying some number of additional coats (and sanding back each time) before you achieve a filled pore structure of the wood. However the result can be superior since many sanding sealers do little to enhance the wood.

MDF needs treating in a similar manner. You need to totally fill and isolate the fibrous structure. An initial coat of thinned varnish is a good idea. Then sand back, and repeat, so it goes.

As you approach the final coats you should become aware that you are sanding back what is for all intents just a perfectly smooth layer of varnish. Not until this is the underpinning layer will you get a perfect glossy coat. If there is the slightest trace of grain, fibre, or any imperfection (such as sanding scratches), you will need to keep adding layers. Done right you actually don't need too many coats, but if the finish is unsatisfactory, you know what to do. 4 coats is a minimum.

There are a huge number of possible varnishes. Ranging from traditional "real" varnishes to all the modern polymer. Personally I like a two pack polyurethane. But this is expensive in all respects. You need special thinner, and it will kill your brushes. 7008 flooring varnish works very well. Seriously hard wearing too. I have never had much luck with the water based ones. Then again I haven't tried any in years, they may be vastly better.

Finally, you can always try spraying. All of the preceding applies, but you can often achieve a good result, especially for smaller pieces with a spray-can of varnish. The pro's of course will often spray a 2 pack polyurethane and be done.

 

[Bones13]

In the woodworking mags I read from time to time, I saw a technique for MDF finishing that involved thinned auto body filler to seal, and level the MDF. You need something rather thick to seal and fill MDF. A couple coats of sanding sealer would probably work.

Sanding out the finish at the end is another bit of work. Wet sanding between multiple coats etc. Consider some clear finish on the top of your paint though, wiping off the fingerprints constantly can get thru a thin layer of spray paint.

 

[skyline889]

I don't if it'll work for pine but for the Koa pens I make I sand it up to 600 grit then I switch to a light duty steel wool to buff out any remaning imperfections. After that I stain it, run some thin epoxy over it to seal up the tiny pores from the grain, shoot a few coats of Lacquer with a Sata gun, after that I'll usually run some wipe-on poly, pen-wax, or briwax, depnding on what kind of finish I want on it. It's comes out smooth as glass.

 

[Garbz]

Hey thanks everyone for the input. The MDF finishing idea was cancelled. Since I now wish to get it looking like my speakers I'll be applying a laminex to it in a cherry oak grain. I'm going to try and find one with a reasonable finish so I may not need to do anything beyond sand down lumps currently in the enclosure and glue the sheets on.

As for the pine Turntable rack. It looks like if I start by sanding it as flat as can be, applying required coats of tint to get it blackish, and then pick a method of choice from what was sugested above. Since everyone suggests sanding I'll probably go all out with the longest method of add a coat, sand it down rinse repeat, and see how I go. Thanks.

 

[ozshadow]

For the piano finish, there is only one way I know to get a trully deep, wet look. In between all coats, use a fine grade of steel wool to scuff the finish between every coat, going in the direction of the grain. Do at least 2 coats of color, more if necessary, and as many clear coats as you want. At least 3 or 4.

You can vary the coat thickness as well, but that should not be necessary in this case.

 

[PinkFloyd]

with MDF you size it with a UPVA / water mix (1 part UPVA to 3 parts water) give it a GOOD 15 coats sanding lightly between coats. Once dry then you can prime it and spraypaint it and the finish will be piano lacquer shiny.

before: (bare MDF)

After: (MDF "sized" with 15 coats of UPVA / water to seal it and then spray painted)

 

[Garbz]

lol do you think I'm made of time. I'd be pushing dedicating 5-6 coats to this project let alone 15 regardless of how nice the end product looks

 

[PinkFloyd]

Quote:

Originally Posted by Garbz lol do you think I'm made of time. I'd be pushing dedicating 5-6 coats to this project let alone 15 regardless of how nice the end product looks

The UPVA / Water size dries very quickly so 15 coats can be applied in next to no time.