New at finishing cabinets - need some understanding

[jd12]

I am gearing up to build a pair of Classix II speakers and am thinking about how I will finish them. I’ve scoured these forums and a few others on ways to paint mdf, but am still confused about a few things.

There is so much varying information when it comes to this since everyone has their own idea of how they want things to turn out, and advice comes from people with different backgrounds. This is why I started this post, to better align the advice I receive with my specific desires. With that being said, all I am going for is simply black cabinets; not flat, not not gloss either. Likely satin. I will not be investing in a spray gun to paint these. I intend to use spray can paint.

As far as technique and products I am thinking of using:

• After the boxes are built, with bu tt joints and titebond, I will likely use Wolf’s elmers glue idea on the end grain of the mdf.
• After sanding down the elmers glue, I will use Bondo body filler to cover all seams and any imperfections.
• Once body filler has been applied/sanded and seams have been covered, I will use a high build automotive filler primer. How many coats will I need? Which products have you guys used with success? I was planning on using Rustoleum’s 2 in 1 filler primer. A big question I have is how many cans should I expect to need to cover 2 classix ii cabinets? I am not sure about the accuracy of the coverage spec.
• Once primed and sanded, I will spray black paint. Again, which product have you guys had success with? Rustoleum Universal black satin is something I have used before and it turned out great (metal chair). The fan tip spray nozzle made for easy coverage. How about Krylon fusion? I have no idea how many coats to expect here either. Can these paints be sanded/ should they be sanded between coats? Trying to figure out number of cans as well.
• I do not plan on using a clear top coat of any kind.

Please share your thoughts on this process and if I am missing anything, or completely wrong about how I am going about this.


Thank you.

[djg]

It took me 1.5 hours to apply PSA (pressure sensitive adhesive) veneer to these cabs. Top, bottom, sides. Front and back are solid wood. I don't have the patience to fine finish MDF. I'll put two coats of shellac on MDF, sand and apply stone texture rattlecan finish.

[djg]

A4eaudio did a nice job on these.

http://techtalk.parts-express.com/forum/speaker-project-gallery/1448048-faceted-gloss-black-hitmakers-speaker-stands-and-subwoofer

[trevordj]

If you are going to use rattle can I highly recommend spending a little extra on SEM high build primer. As all uncatalyzed primers, you have to let it sit for quite a while before you can sand it but I think it gives better results. Make sure and use a block as much as possible for your sanding. How thick you build it is very dependent on how out of true your surface is, so that's hard to answer. I would estimate you will need 3-4 cans? Hard to say.

For color I would also recommend SEM stuff, its the best quality rattle can I have used. Also get yourself one of those clip on triggers so you don't get paint on your fingers and you have better control.

I would highly recommend reconsidering clear coat. I would recommend a catalyzed clear for durability. Something like this:

https://www.eastwood.com/eastwood-s-...YaAjTwEALw_wcB

[djg]

Check out trevordj's build thread, jeez.

[tvrgeek]

There was a recent thread on glue joints shrinking. PVA glue is the worst offender ( white and yellow carpenters" glue.). I almost don't use it any more.
Some argue for epoxy, I suggest powered resin glue. It is what real woodworkers use.

How much effort and what supplies is a choice. A top notch piano finish takes a lot of time and a lot of materials. If you don't have a compressor and gun, you are a bit limited in choices.

My top notch finish is poly resin., 2K primer, 2K color. Automotive poly. I have not used the new water based stuff. But my most recent is my HT center where only the baffle is viable. It has two spit coats of thinned poly varnish and rattle can hammer-tone. Satin black on the box which is not viable. Works for the need.

I might suggest browsing the woodworking forums.

[a4eaudio]

I would recommend satin.

• After the boxes are built, with butt joints and titebond, I will likely use Wolf’s elmers glue idea on the end grain of the mdf.
• After sanding down the elmers glue, I will use Bondo body filler to cover all seams and any imperfections. I think I would do Bondo first then elmer's glue, but not sure. What is your take Wolf ?
• Once body filler has been applied/sanded and seams have been covered, I will use a high build automotive filler primer. How many coats will I need? Which products have you guys used with success? I was planning on using Rustoleum’s 2 in 1 filler primer. A big question I have is how many cans should I expect to need to cover 2 classix ii cabinets? I am not sure about the accuracy of the coverage spec. I use Rustoleum Filler Primer (see pic below) and know many have, but this isn't necessarily because it is the "best" but because it is easily available and pretty cheap. Might be able to get away with 2 (or 3) cans but as trevordj points out, depends on the surface you are starting with.
• Once primed and sanded, I will spray black paint. Again, which product have you guys had success with? Rustoleum Universal black satin is something I have used before and it turned out great (metal chair). The fan tip spray nozzle made for easy coverage. How about Krylon fusion? I have no idea how many coats to expect here either. Can these paints be sanded/ should they be sanded between coats? Trying to figure out number of cans as well. I would normally say that if you used it before with good results then stick with it. I hated the paint I used and won't use it again, bad paint makes it so much more work. Seeing trevordj's builds I would go with SEM simply based on his recommendation, even though I think it is a lot more than the cheap paint at Home Depot. trevordj I looked up SEM and saw a few different options, what black paint do you recommend?
• I do not plan on using a clear top coat of any kind. I don't think I could buy the expensive stuff trevordj linked. I usually use spray polyurethane for some added protection and its pretty cheap ($4/$5 a can)

[Wolf]

Spray polyurethane on enamels tends to not adhere well, and can peel off. Lacquer and acrylic-clear are better top-coats for enamels.

I tend to not prefer Rustoleum products, and have better luck with the Duplicolor/Krylon family. Krylon Fusion is really good paint, and bonds well to pretty much anything- including plastic. The Ultramax is the next step up and is good as well. I usually use Duplicolor Filler Primer and Duplicolor Primer Sealer once the primer is butter smooth.

You want basic black? Seal and use filler primer, primer sealer, and chalkboard black paint. Hand-Sand and repeat till satisified between steps, allowing 24 hrs between coats, hopefully in dry or low humidity weather. Sand with 250/300/400 grits for primer. Sand the sealer with 400/1000. Maybe sand with 400 on the chalkboard paint, reapply and you likely should be good. When happy with the black, finish coat with VHT Nite-Shades blackened-clear.

I would Bondo after the Elmer's and a brief sanding, as the Elmer's is to seal, whereas the Bondo will fill in voids. I don't normally use Bondo myself.

Later,
Wolf

[jtheisen521]

One step missed, after sealing the edges, be sure to seal the entire box prior to priming. I like using a shellac based product such as Zinnser BIN for this. Some just use a 50/50 mix of wood glue and water. Whatever you use please be sure to seal the inside surfaces as well (often overlooked). Sent from my iPhone using Tapatalk

[Kornbread]

This is the way I'm going on the next painted project.

[jhollander]

If you are not spray gunning and using but joints, imo rattle cans are not going to be any advantage over rolling with a high quality latex trim paint, Benjamin Moore or Sherwin Williams super paint. If flat was in the mix General Finishes Milk paint would be my first choice. Lighter colors and less gloss shows the fewest flaws. Painting is the hardest most time consuming finish to get right.

[trevordj]

I would recommend satin.

• After the boxes are built, with butt joints and titebond, I will likely use Wolf’s elmers glue idea on the end grain of the mdf.
• After sanding down the elmers glue, I will use Bondo body filler to cover all seams and any imperfections. I think I would do Bondo first then elmer's glue, but not sure. What is your take Wolf ?
• Once body filler has been applied/sanded and seams have been covered, I will use a high build automotive filler primer. How many coats will I need? Which products have you guys used with success? I was planning on using Rustoleum’s 2 in 1 filler primer. A big question I have is how many cans should I expect to need to cover 2 classix ii cabinets? I am not sure about the accuracy of the coverage spec. I use Rustoleum Filler Primer (see pic below) and know many have, but this isn't necessarily because it is the "best" but because it is easily available and pretty cheap. Might be able to get away with 2 (or 3) cans but as trevordj points out, depends on the surface you are starting with.
• Once primed and sanded, I will spray black paint. Again, which product have you guys had success with? Rustoleum Universal black satin is something I have used before and it turned out great (metal chair). The fan tip spray nozzle made for easy coverage. How about Krylon fusion? I have no idea how many coats to expect here either. Can these paints be sanded/ should they be sanded between coats? Trying to figure out number of cans as well. I would normally say that if you used it before with good results then stick with it. I hated the paint I used and won't use it again, bad paint makes it so much more work. Seeing trevordj's builds I would go with SEM simply based on his recommendation, even though I think it is a lot more than the cheap paint at Home Depot. trevordj I looked up SEM and saw a few different options, what black paint do you recommend?
• I do not plan on using a clear top coat of any kind. I don't think I could buy the expensive stuff trevordj linked. I usually use spray polyurethane for some added protection and its pretty cheap ($4/$5 a can)

I like this stuff for color:

https://www.semproducts.com/product/multimaxtm

The rattle can primer I have had luck with is this stuff:

https://www.semproducts.com/product/...rimer-surfacer

I will say that about 1.5 years ago I really dedicated myself to finally learn how to spray automotive paint with a gun. Since I have gone that route I haven't used much rattle can stuff other than for guide coats. One thing to consider would be using polyester primer to seal the wood and hide your end grain, it can be brushed on. Without trenching out the joints you will still likely get the joints showing through but you can get it looking pretty good. I personally do not use the glue method, I just spray polyester primer after filling any defects with filler.

I would use this:

http://www.evercoat.com/product-deta...art/100710/us/

You can brush it on, let it cure, then block sand it. I imagine brushing it you won't get as high a build as spraying but I think it will get you there. Polyester primer is basically very thin body filler that can be sprayed.

So, if you are willing to try polyester primer but not do an HVLP gun then the process would be:

Sand wood to 220 grit, trench the joints if you choose, fill defects with body filler, sand flat, brush on polyester primer, block sand dry (do not wet sand polyester primer or body filler) with a guide coat until your cabinet is covered with primer and flat, work the grits to 400 grit then spray your base and clear. If you use a catalyzed clear you can color sand and buff after it cures.

If you don't want to try the polyester primer then it would be:

Sand wood to 220 grit, trench if you choose, fill defects with body filler, sand flat, spray high build primer, block sand with guide coat until flat and covered, work the grits to 400 and then spray base and clear.

[trevordj]

There was a recent thread on glue joints shrinking. PVA glue is the worst offender ( white and yellow carpenters" glue.). I almost don't use it any more.
Some argue for epoxy, I suggest powered resin glue. It is what real woodworkers use.

How much effort and what supplies is a choice. A top notch piano finish takes a lot of time and a lot of materials. If you don't have a compressor and gun, you are a bit limited in choices.

My top notch finish is poly resin., 2K primer, 2K color. Automotive poly. I have not used the new water based stuff. But my most recent is my HT center where only the baffle is viable. It has two spit coats of thinned poly varnish and rattle can hammer-tone. Satin black on the box which is not viable. Works for the need.

I might suggest browsing the woodworking forums.

This is pretty much my process too. I still use PVA glue though. Rather than poly resin, if I am finishing with color, I spray polyester primer. Its really the same stuff as resin it just has some solids added along with some additives to help it sand easier. If I am finishing a wood clear then I spray a specialty resin called Simtec 28x50 followed by 2k clear.

The best place I have found for information about finishing woods is guitar building forums. The Simtec 28x50 is the same stuff Gibson and Fender use to seal the grain before 2k clear.

https://www.plasticmaterials.net/28x...g-clear-sealer

[tomzarbo]

I know you said you would use but joints, but if there is any way you could do miter joints, that alone would make your like 1000% easier as far as having smooth surfaces, long term. Seams don't show on miter joints.

If you have a friend who has a good table saw, I'd strongly suggest that. Miter all corners if possible. Seams will almost always show on cabinets with but joints unless you are extremely diligent and a little lucky. It may take a year or more, but most joints will eventually show.

TomZ

[Geoff Millar]

PVA glue isn't that bad when used as intended, I've used it in all my builds but I've used screws as well. My first cabinets were mitered as suggested by Tom Z, and that definitely gives a better finish than butt joints. But if you don't have accurate enough equipment to miter for a decent join, you'll end up using filler anyway. A PETT member suggested that PVA and MDF dust make a good filler, I found it OK. My mitered cabinets are now 6 years old and there's no sign of shrinkage yet.

My other builds have been butt jointed, just because it's easier and I don't have a table saw to do a really good miter cut.

However, the finish on my Jimi Hendrix decoupage Classix II, never that great in the first place, has suffered with time although the PVA joins have held up very well. I used Mod Podge as a glue and sealer and it's never dried properly; it attracts dust and gunk which can't be cleaned off.

I haven't found a good solution for butt jointed MDF edges, for my next build I'll try one of the excellent suggestions in this thread.

Geoff

[tvrgeek]

Not glue guns, PAINT guns. Hot glue is for kids crafts or holding crossover parts down.

I use almost exclusively butt joints in MDF and particle board. As I always route a generous radius, all a miter does is change where the glue line is. No help. In solid woods, I am showing off my joinery anyway.

I have been using Dap Weldwood 203 1 lb. Plastic Resin Wood Glue. There are other brands and larger more economical sizes. Mix it with water to tooth-paste thickness. Longer working time than PVA or epoxy which helps a lot when many pieces and odd shapes. But it also means it should sit overnight to cure. I use a pin nailer to hold things in place while the glue dries. No need for screws as the glue is stronger than the wood. Tape works fine too.

Guys, this is simple. Go cut up a bunch of small bits of MDF and PB. Try all the ideas. Do what works for you. I let my test pieces sit 6 months. Most issues showed up by then. Another 6 months, no difference in the "good" solutions, but the "bad" ones got worse.