How can I finish my wood shelf project to match my decor?

[DaveC426913]

TL;DR

Made of finish-grade ply, want to spray it white, but I'd like a smooth surface

Just made a little shelf for the bathroom. It's made of finish-grade plywood. If I just spray it, it will look like spray-painted wood. (I'd usually just use Tremclad gloss white). Can I put some sort of sealant coat on it so the spray coat is smooth? Do I put a top coat of shiny on it afterward?

Everything else in the bathroom is standard IKEA-esque white veneer.

 

[berkeman]

Is there a reason you aren't using melamine for this?

Paging @phinds

 

[DaveC426913]

Is there a reason you aren't using melamine for this?

Paging @phinds

I... hadn't thought of that.

But I think it may be beyond my skillset. I've never done melamine work , and it's curved.
The shelf is a half moon with ledge.

It is literally a clock blank from a craft store that I cut in half.

Paging @phinds

Thanks. I had made a mental note to Cc Phinds, but forgot.

 

[phinds]

Dave, you can cut a curve out of melamine just as easily as with wood but if you're thinking of bending then of course melamine is out of the question. I would use melamine over plywood because often even with paint, the grain shows through with plywood and not it an attractive way. If you are STAINING it, then plywood grain might be interesting but with paint I don't think it looks so good. A nice smooth melamine surface is better.

In any case, since it's a bathroom thingy, use a couple of coats of paint and don't forget to do the back. Even though you can't see it, it can absorb moisture, so don't let it.

 

[sophiecentaur]

Is there a reason you aren't using melamine for this?

Paging @phinds

That would mean starting again from scratch. Plus, what would you do for a good curved edge?

Dave, you can cut a curve out of melamine just as easily as with wood but if you're thinking of bending then of course melamine is out of the question. I would use melamine over plywood because often even with paint, the grain shows through with plywood and not it an attractive way.

If you were prepared to fit the available pieces of 'finished' material then it could save some time but for any non-standard shape / size there would be the 'endgrain' problem. There isn't a grain on melamine so the edge would need filling so that would look different, however you finish it. If you're prepared to take longer than you might want to, you can fill and prime edges and chamfers.

But you probably only need to spend more time on what you've got and use several coats of spray on a well prepared surface and 'practice spraying properly' (My efforts are not good so do as I say and not as i do).

Fablon was popular at one time, lol. I see it's still available.

 

[DaveC426913]

Sorry. When berkeman said "melamine", for some reason my brain went to "veneer" - as in: applying to my existing project.

I have actually built custom units out of melamine. In fact, I have some spare boards from my last project.

But nah. I like my little half moon shelf.

 

[DaveC426913]

In any case, since it's a bathroom thingy, use a couple of coats of paint and don't forget to do the back. Even though you can't see it, it can absorb moisture, so don't let it.

So, this is where I am now.

A suspect that a couple of coats of paint will have it looking - and feeling - like painted plywood. Very matte and rough. I guess that's because I prefer to spray rather than brush so I get a nice even coat and no brush marks. But it's very thin.

I suppose you would advise me to "sand, sand and sand some more" with increasingly fine grit paper. I was hoping a coat of sealant or two would substitute.

 

[phinds]

I suppose you would advise me to "sand, sand and sand some more" with increasingly fine grit paper. I was hoping a coat of sealant or two would substitute.

Depends on the wood. If the plywood is Douglas fir then sanding will do little good because of the significant difference in density between early wood and late wood. If it's a fine grain like Baltic birch then you hardly need to sand.

 

[Spinnor]

I... hadn't thought of that.

But I think it may be beyond my skillset. I've never done melamine work , and it's curved.
The shelf is a half moon with ledge.

It is literally a clock blank from a craft store that I cut in half.


Thanks. I had made a mental note to Cc Phinds, but forgot.

View attachment 356811

"Paint" the end plywood laminations with several coats of wood glue, let cure between coats, and then sand. That should act as a sealer/filler. One coat of glue might do? Google says,

Yes, cured wood glue on wood can be painted if it is sanded down smoothly, as most wood glues are designed to be paintable once they are fully dried and sanded to remove any noticeable glue residue; however, it's important to ensure the glue is completely cured before painting and to use a fine-grit sandpaper for a smooth finish.

Then paint and sand between coats. You might also sink the two black screws beneath the wood surface and spackle and sand the voids above the screws.

A picture of the final product please.

 

[DaveC426913]

I like that. Painting the end grain with glue would give a good finish and fill any gaps that invariably occur in plywood ends.

In this case the end grain is only on the curved edge.


(Argh. Using wood glue requires the extra step of thawing the glue out after having been stored in my below-zero work shed.)

 

[marcusl]

You can use a grain filler like AquaCoat. Sand all surfaces smooth to 180 grit, apply a seal coat (Zinsser shellac, polyurethane cut with mineral spirits, etc.), dry, and apply filler according to directions. After about 6 coats, sanded in between, you should have a smooth surface ready for priming then painting.

 

[marcusl]

BTW, I wouldn’t trust any glue that froze. If it were me, I’d throw it out.

 

[DaveC426913]

After about 6 coats, sanded in between...

OK. No.

 

[bdrobin519]

Within my experience I would use binz shellac primer and sand with fine grit in between at least two coats. This will eliminate any stains or fish eyeing from old cleaning products that could form. Then for the finish coat use sherwin williams emerald water cleanup urethane trim paint. Mix with Floetrol and apply with disposable foam roller and fine hair small brush for corners. If you have access to a HVLP sprayer i recommend using that but either way it should turn out very smooth with the hardness of urethane.

 

[Spinnor]

BTW, I wouldn’t trust any glue that froze. If it were me, I’d throw it out.

Google said that freezing was not necessarily a death sentence for wood glue. Following the Pennsylvania Dutch advice, "use it up, wear it out, make do, do without" might apply. The thawed glue could be tested, glue two pieces of wood together or put some to cure on scrap cardboard. If the cured glue is hard and the pieces of wood do come apart the glue is probably good to use.

 

[DaveC426913]

and the pieces of wood do come apart

< not

?

 

[Mark44]

< not

?

Pretty sure he meant if the two pieces don't come apart.

 

[DaveC426913]

Pretty sure he meant if the two pieces don't come apart.

My point exactly. To-wit:

Is there supposed to be a "not" in there?

 

[Mark44]

My point exactly. To-wit:

Is there supposed to be a "not" in there?

You seemed unsure in your post with the ? at the end.

 

[Spinnor]

I did an experiment with some Titebond wood glue that is probable the better part of 10 years old. Pieces of wood were glued together and at the same time a small sample of glue was wrapped in Saran wrap and frozen for about 24 hours. The frozen glue was then thawed and two more pieces of wood glued together. 10 hours latter I tried breaking the glued wood pieces apart at the joints. In all cases the glued joints were stronger than the wood, the glued joints did not come apart. So one freeze cycle did not seem to ruin the glue but keep in a shed over many freeze thaw cycles probably needs to be in a land fill.

 

[DaveC426913]

I did an experiment with some Titebond wood glue that is probable the better part of 10 years old. Pieces of wood were glued together and at the same time a small sample of glue was wrapped in Saran wrap and frozen for about 24 hours. The frozen glue was then thawed and two more pieces of wood glued together. 10 hours latter I tried breaking the glued wood pieces apart at the joints. In all cases the glued joints were stronger than the wood, the glued joints did not come apart. So one freeze cycle did not seem to ruin the glue but keep in a shed over many freeze thaw cycles probably needs to be in a land fill.

Thanks for this. I warmed the glue over my space heater until it was liquid and then mixed in some water. Seemed to work OK.

But...

 

[DaveC426913]

Weelllll.. this was a bust I think.

I've added a few coats of spraypaint*, sanding in between. It was coming along OK, but this last coat went awry. As it dried, it started to wrinkle up. When I went to sand it, the wrinkles ripped off, and now the finish is ruined.

*which turned to be more off an off-white in the pink range - not a tragedy since my bathroom has a bit of a pink tinge to it.

You can see here that when I went to sand down the wrinkles, they came off right down to the wood:

I have a few theories why this happened:

• I did not prime or seal the wood before starting. Maybe I should have. Although the paint does say no priming necessary.
  
  
• Maybe I should have used a paint that's specific for wood. This is what I used:
  
  
  Altough it does say it's usable for wood.
  
  
• I picked up the can in a hobby surplus shop in a discount bin. It could be years old. The batch# on the bottom says 423220001 HL2208PB NFP 1.40 00:04. No idea if there's a year encoded in there.
  
  
• The sandpaper I'm using is 600grit, wet. (I'm not using it wet.) Maybe it's a little too fine.
  
  
• Maybe I am not letting everything dry sufficiently - be it paint or glue. Exacerbated by the low temps when I have it in the shed, resulting in longer drying times. (though I do bring it in overnight to dry.)
  
  
• I have been bringing the work (and the paint and the glue) between warm house and freezing shed. I wonder if what's happening is that the moisture in the wood or in the glue (which ought to be dry) is leeching out of the wood and freezing under the paint.

Regardless, I think I'm going to regelate this attempt to "prototype" status and start again with what I've learned.

This is a piece that I - and everyone else - are going to see every single day close up, since it's at eye-level right next to the sink. So I'm trying to do this to a standard higher than my usual "rough nailing strips and deck crews" work.


Besides, I'm not happy with other aspects, for example: the joints. You can see where I didn't join it very well with a screw because I was afraid it would split the plywood - even though I pre-drilled it. That'll be really obvious.

Also, I missed with the nail gun along the straight edge - that ply is only 1/4" thick.

Luckily, I have a second clock face blank, so it's no loss to start again. This time I'll do a proper job sanding before I assemble it, and follow whatever advice you guys offer about the paint job.

And maybe I'll use actual white paint this time.

 

[Spinnor]

Looks like the spray paint worked OK on the vertically oriented piece of wood in the picture. The surface with the imperfections is hidden, ignore?

You can get a pretty good finish painting with a brush if you use an oil based product, sanding between coats, though the oil will really soak into the wood especially on the end grain requiring several (at least) coats. Eventually you should be able to build up enough coats to get a good finish.

Even water based gloss trim paint can be brushed to give good results, it dries quickly and needs fewer coats.

Our eyes are pretty good at picking out flaws in painted surfaces, more so if the light hits the work just right.

 

[DaveC426913]

Looks like the spray paint worked OK on the vertically oriented piece of wood in the picture.

Sorry, you're looking at it lying down. That "vertically-oriented" surface you're seeing is actually the underside of the shelf.

The surface with the imperfections is hidden, ignore?

No, the flawed surface is front-facing, under the shelf - where my hand is. Pretty obvious. The crummy joint is in the upper left - also pretty obvious.
This the correct orientation.

You can get a pretty good finish painting with a brush if you use an oil based product, sanding between coats, though the oil will really soak into the wood especially on the end grain requiring several (at least) coats. Eventually you should be able to build up enough coats to get a good finish.

Even water based gloss trim paint can be brushed to give good results, it dries quickly and needs fewer coats.

Yeah, maybe I'll paint it on next time. Spray paint goes on so thin that it takes forever to build up an opaque layer.

 

[sophiecentaur]

The sandpaper I'm using is 600grit, wet. (I'm not using it wet.) Maybe it's a little too fine.

You should aim at several different grades on the way. There are many Youtube videos about how to sand 'properly' Look at several and take an average between sloppy and anal retentive. A horizontal surface is easier to paint and avoid runs or drips.

 

[rbelli1]

practice spraying properly

Watch some videos on car body painting. In particular, study how they handle the end of the stroke. My spray painting went from absolute drippy mess to mostly not a drippy mess the first time I used the technique in those videos.

BoB

 

[DaveC426913]

Watch some videos on car body painting. In particular, study how they handle the end of the stroke.

I start off the edge and finish off the edge to get an even coat. Have things progressed since my day?

My bigger issue is knowing when a coat is thick enough and stopping before it gets gloopy.

I have always been impatient that way, since my Airfix/Revell/Monogram days, when I'd be trying to paint cockpit parts that hadn't even had the glue dried yet.

 

[rbelli1]

Have things progressed since my day?

That sounds about right. Before I knew this I managed to get nothing but a sloppy mess down both sides of whatever I was painting.

BoB

 

[hutchphd]

For interior fresh wood I have always been a fan of B-I-N by Zinsser as primer. Not cheap though.

 

[bdrobin519]

I said the same thing! You can't beat shellac, especially when you're dealing with old wood surfaces that probably have years of different cleaning soaps soaked into them. Check out my comment let me know and Dave what you think or can add to the process.