[nlitworld]

It would be great it we had a sticky thread focusing on "Painting / Finishing MDF - Best Practices" as there are a ton of little tips scattered among build threads over the years.  Also, it would be fun watching experienced woodworkers debate the pros / cons of their favorite glue. 

I've written out step-by-step instructions probably a dozen times to help people along the way, and yet I've been too lazy to make a sticky Best Practices post. Lol. You're right though, it would be amazing to have one central location for a good tutorial. Peter has done amazing with his cabinet glue up videos (thank you again by the way!) so I just need to sit and make a good post with photos and hopefully people find it helpful. I'll have some free time around work next week so I'll try and post up something then.

[Peter J]

.  Also, it would be fun watching experienced woodworkers debate the pros / cons of their favorite glue. 

It all tastes like poo. I think glue color is the best way to decide.

[Huskerbryce]

Thanks for all the insights.  It seems painting and finishing is more of a science and art than I even thought.  Ive tried painting mdf in the past with mixed results.  Usually I veneer with wood.  This time around I am hoping to do more of a gloss black finish with a high sheen.  Obviously I dont know how to accomplish that in my garage.  Sounds like it would be next to impossible to do without a professional and associated paints, primers and equipment.  I appreciate the advice.  Ill check out the past step by step threads.

[Peter J]

Gloss black can be accomplished with conversion finishes formulated for woodworking, but supply chain is more obscure unless you have access to cabinet and furniture industry suppliers. Both would require spray equipment and a good respirator.

You could also talk to cabinet shops well versed in custom work as well as body shops. The key to any good finish is the prep work. Paint will hide nothing in the way of surface flaws. It's generally harder to get a good painted finish than it is to finish wood or wood veneer. That sometimes surprises people.

[sledwards]

My Oticas were professionally painted at custom auto shop. They used Evercoat Slick Sand as the primer (2 to 3 coats, final sand to 800). It is polyester based and uses an activator.

[nlitworld]

My Oticas were professionally painted at custom auto shop. They used Evercoat Slick Sand as the primer (2 to 3 coats, final sand to 800). It is polyester based and uses an activator.

Evercoat Slick Sand is a great option. Polyester primers are basically sprayable body filler, will coat and evenly absorb nicely into the mdf and generally easy to spray with a standard 1.8mm nozzle spray gun. Other heavier building polyester primers like their Super Build are great for filling and sanding, but usually require an even bigger 2.2 nozzle spray gun.  Talk about a fire hose!

From there, it's a quick and easy urethane sealer (non-sanding thin primer) and right into spraying color.

[jmimac351]

I've written out step-by-step instructions probably a dozen times to help people along the way, and yet I've been too lazy to make a sticky Best Practices post. Lol. You're right though, it would be amazing to have one central location for a good tutorial. Peter has done amazing with his cabinet glue up videos (thank you again by the way!) so I just need to sit and make a good post with photos and hopefully people find it helpful. I'll have some free time around work next week so I'll try and post up something then.

I think that would help a lot of people... and probably give many the confidence to build their first speaker.

[Huskerbryce]

Peter, Rusty, Jmimac, Nlitworld, sledwards, tyson and anyone I forgot, thanks for all the info and insights.  I looked into auto shops painting them along with some woodworking shops.  Everyone basically led me to a path of $2000 to do it.  My DIY mind is averse to spending that kind of cash to let someone else paint “my” diy speaker.  Im going to do this in my shop.  Im no pro, probably wont be even be close to perfect but here we go.  Leaning toward something between a piano gloss finish and a soggy looking awful pitted matte finish.  Lol.  We shall see what I can do.  I have a few ideas to mask my “suck” imperfections.  Thinking a high build primer, lots of sanding, lots of time, lots of impatience and lots of minor mistakes leading to a finish that is livable.  Any ideas or help or opinions with specific ideas or products will help.  Thanks.

[nlitworld]

I'll message you with some help on a DIY non-suck paint job  including part numbers and step by step info. I'll also have some time at work this week to make a sticky post on DIY automotive finish. Biggest general piece of advice is to practice patience and pay attention. After that, just knowing that worst case sand it down and do it again.  Also $2K is a little bit steep so most shops were likely pricing you out to not have to take on the project. Bumpers and fenders are generally more profitable.

[Rusty Jefferson]

....Thinking a high build primer, lots of sanding, lots of time, lots of impatience and lots of minor mistakes leading to a finish that is livable.  Any ideas or help or opinions with specific ideas or products will help.  Thanks.

If you have spray equipment and some experience, no reason not to tackle it yourself. If you have neither, consider the duratex product. I have a friend who recently built a nice pair of speakers and finished them with it that turned out quite nice. He used a foam roller which minimizes the texture but leaves just enough to hide imperfections and leaves a satin sheen. He also tinted it. The finished speakers in his room look (and sound) great.

[jmimac351]

If you have spray equipment and some experience, no reason not to tackle it yourself. If you have neither, consider the duratex product. I have a friend who recently built a nice pair of speakers and finished them with it that turned out quite nice. He used a foam roller which minimizes the texture but leaves just enough to hide imperfections and leaves a satin sheen. He also tinted it. The finished speakers in his room look (and sound) great.

Thanks for sharing this about Duratex / making it smoother.  I've wondered how that would turn out. 

@Huskerbryce Also do a search on here for "General Finishes Milk Paint".  That's used for refinishing cabinets / furniture.  I haven't seen the finished product in person or used it... but it's in my pile of stuff to dig into.  I'm also going to build a pair of NX-Otica and will probably finish them in white.  Mike Lundy has used the Milk Paint here: https://www.audiocircle.com/index.php?topic=135561.40

I wonder how the Duratex would compare to the General Finishes paint for ease of application / looking good and hiding things. Another thing to consider, if it goes on easy and is not meant to be a perfectly smooth / mirror gloss finish, it may make it easier to touch up a spot here or there down the road.

https://generalfinishes.com/wood-finishes-retail/water-based-paints-glazes/milk-paint

[poseidonsvoice]

Rusty,

Are those Joe Rasmussen’s Elsinore speakers?

Best,
Anand.

[Rusty Jefferson]

Rusty,

Are those Joe Rasmussen’s Elsinore speakers?

Best,
Anand.

Yes they are. 

[Huskerbryce]

After a couple weeks of sealing, sanding and priming I decided on a color.  I primed with a rustoleum high build auto primer.  Put multiple coats, lightly sanding from 220-320-400 grit 3M paper.  After a couple weeks of that I was happy with the smoothness.  I applied a GM auto paint in the color Iridium metallic.  Added a clear coat.  Waiting for the clear coat to cure and then I plan to lightly buff it with miguels polishing compound. 

[Danny Richie]

Wow, looking good.

[Rusty Jefferson]

Indeed. Real nice color scheme. Hope you got the results you were after.

[Huskerbryce]

So far, I’ve got a very nice finish. I do not see any seams. I think once the clear coat is cured, I feel I can buff and make them shine like glass. But if I buff, I think I will just buff the side baffle first and see what it looks like before I attack the front baffle.  Planing to use miguels auto polishing compound with a light buff.  Nothing too aggressive. 

[Huskerbryce]

I am slightly nervous doing anything else to these babys.  I spent 40+ hours on sanding, sealing, priming, finishing, painting and coating.  I have no experience with a polishing compound other than a youtube video and my imagination on a thought experiment gone horribly wrong.  Does anyone have any experience with a polishing pad on a clear coat like this with something like miguels or another compound?  Id hate to ruin a good thing……

[nlitworld]

It's actually pretty easy, provided you go slow and take your time. Are you using an actual buffer or are you foing this on a drill with little 3in pads? Also, what type of clearcoat did you use? 2 part catalyzed clearcoat (like Spraymax 2K Clear) you can be a lot more aggressive with your polishing steps but a 1k non-catalyzed aerosol clear you can't get too crazy. So as a few quick tips, apply a few drops of compound to the pad and reapply only 1-2 drops as necessary. Do not overload the pad or it will basically hydroplane across the panel and not work properly. Keep a squirt bottle and microfiber towel around to clean up as you go along and can also keep the panel moist partway through application. Work in small sections where normal car is 2'x2' but this would be 1'x1' sections. Meticulously work your way around the speakers with the first compounding step, then move on to the polishing second step. Send me a message with any specific questions and I'll try and get you all set. I always joke with customers at work, "worst case scenario just sand it down and do it again". 

-Lloyd

[Huskerbryce]

So, Nilt…you are hired.  Do you live in the cincinnati area?  😂.  I used a 1k clear coat.  I never planned on anything too aggresive.  Im on the fence wether or not I even need to buff.  Ill add a close up of what im looking at.