My DIY speaker, the P3H Audio M2 (1 Viewer)

[Ryan Peddle]

I have been working on this speaker for a few months now. I have aspirations to design and manufacture my own line as a small business on the side, so I figure a good place to start is the name. This is it the P3H Audio M2. The next step is finishing the outside of the speaker which to start off I am aiming for a piano gloss black. Picked up some Behr Premium Plus Hi-Gloss Enamel paint to put over the primer. If you have any tips on acheiving a super gloss I'd love to hear them.

5.25" wool cone woofer
1" Fabric dome tweeter
3/4" MDF material
Ported design and tuned to 47Hz.

 

[BlakeN]

If you want to do a high gloss piano black be prepared for pain. Its the hardest finish to get right period. There are plenty of detailed guides on how to do this but I will go over the general points.

1) Fill every tiny tiny hole or ding you can find with wood filler or better yet coat the whole enclosure in bondo and sand it down. If you can feel a bump with your finger nail its going to show up.

1a) If you didn't cover the whole thing with bondo watter down some wood glue and paint any exposed cut edges. Cut mdf edges soak up paint like a sponge and they will look like crud. The glue helps.

2) Sand the whole enclosure down with 200 then 400 grit.

3) use tack cloth to pick up any dust particles on the enclosure.

4) make sure you are in a well ventilated yet dust free environment. If you are in a shop or garage make sure to lean up any saw dust as best you can before painting. Nothing sucks more then getting dust particles on your mirror finish.

5) If you are going to be doing this in any professional manner get yourself an HVLP Gun and a good compressor. You could also get a cheap HVLP turbine unit. They are a quite a bit cheaper then even just a compressor. It won't work as well but a light years ahead of a spray paint can. This will at least let you try out a few speakers before going with a full system.


6) Tip: use gray primer not white.


Now its time to paint. All coats are THIN coats if you think you aren't putting on enough you are putting on just enough. Put down 2 coats of primer (letting each dry for 30 minutes) then sand with 400. Use your tack cloth to pick up all paint dust between every coat. Put down 2 more coats and wet sand with 800/1000. Now take a look at your box. Does the primer look constant? Is it glass smooth? If not put down some more and keep wet sanding. Use broad sweeping LIGHT strokes when sanding down try to grind it down. Use a spray bottle to keep the area wet. The water is not only a lubricant but it is also used to wash away the sanded off material. Make sure you are using quite a bit of water. When you think you have the primer constant and as smooth as possible tack it off and start laying down the black. These coats should be very light. Sand with your 1000 between every coat and tack off the dust after every sanding. You will probably be looking at about 5-6 initial coats then for the last 2 switch to the highest grit sand paper you can find 1500/2000 if you can get it. Now its time to put on the clear. Do this just like the others but on the last coat make sure you are using full strokes and applying it as evenly as possible. Let it dry over night and see how it looks. If its perfect leave it if not sand it down and try again. When you are happy get out some high gloss car wax and wax them down.

If you want to see how good your job was take the speakers out into the sun and get yourself a piece of graph paper. Look at the paper in the reflection. If all the lines are straight and the paper looks perfect then you did a perfect job.

You are now done. It could take anywhere up to a month or even 2 for your speakers to cure so be careful with them.

If you are trying to turn a profit on these I would HIGHLY suggest you switch to some type of veneer or charge $500 per speaker.

 

[Ryan Peddle]

Thanks a lot Blake. I have just picked up some 600 grit waterproof sandpaper, and have access (through Canadian Tire) to up to 1500 grit wet sandpaper. I will pick up some tack cloth, which I have used before. Do you sugest foam rolling the coats on, or brucking them on.

As well, do you sugest doing all the sanding by hand or use a electric sander (I have the Ryobi Corner Cat.

I have also read some info on Glue Size, which is mixing one part wood glus and 10 part water to use as a good sealant for tiny cracks (seams) and scratches. Then prime over that using you method.

Thanks for all the help.

 

[BlakeN]

You are going to want to hand sand it. You can use an electric sander on the primer and after the first 2 coats of black but after that switch to hand sanding. As far as brush or roller my best advice is neither to get a good high gloss paint job you MUST spray. There is a reason they don't paint cars with brushes. I have no idea how it will turn out if you do it by hand but If you want to try use a roller. You want a 1/4" nap mohair roller. I don't know how thick that paint is but you want it thin so think about getting some paint thinner. I would also use a dry roller method. You need 2 roll trays and a spray piece of mdf. Put your paint in tray 1 and get a small even coat then roll it out in tray 2 to get as much or the excess off and then roll out a few strokes on your spare piece of mdf to even it out and then finally roll it onto your speaker. After a few reloads you should be able to pick up enough paint in tray 2 to roll out so alternate between (tray 1 -> tray 2 -> MDF) and (tray 2 -> MDF). Remember even though you are rolling you are still going for thin coats more then 100% coverage. You should still be able to see primer after the first and possibly even the 2nd coat. On your final coat go for full even strokes with 100% coverage.

 

[Mattak]

I would black lacquer it. Hit it with a couple coats of sanding sealer and then at least 3+ coats of lacquer, sanding between sealer coats and the first couple lacquer coats. Despite what others may say, I've worked on an entire mdf trimmed house interior (4" baseboard, wainecoting, door and window trim) lacquering all of it (white lacquer, however) and it works great with the proper prep. I think you're going to have a very hard time getting a latex based paint to give you a piano black finish. Either way I think you definitely need to spray.

 

[Alan M]

I agree with all the above,but would add,

if you really want a high gloss black finish,When finished with the black,sand again with 440 grit sandpaper.At this point,spray a few coats of clear finish( I spray 5 coats).Wait 24 hours for the clear to harden,then sand with 1200 grit paper.This will get rid of any imperfections in the clear coat.

Hand rub 3m's glaze finish into the clear to bring out the high gloss.You'll have a finish pro painters would be proud of.

 

[Greg_R]

If you have a slow speed grinder (or buffer) in your garage then look into wood (or automotive) polishing products. My procedure:

- Prep MDF and joints with Bondo or epoxy resin + filler (West systems, etc.)
- High quality dark primer (keep coating until MDF stops sucking in the primer)
- Rough sand the primer with 80 grit (i.e. knock of any major lumps)
- Use oil based paint or spray laquer and coat. Use a sanding block (keeps paint level) and sand with 220 (knocking off any imperfections). Clean all the paint dust off before the next coat. Note that you don't have to sand to very high grits on each coat... we are just trying to keep the paint level at this point.
- Keep adding coats of black, sanding between each coat. 3 coats is an absolute minimum.
- Now go through all the wet sanding procedure outlined above. This will make the paint very flat.
- Finish with oil based Poly or clear laquer. Sand to 600 grit w. paper and then use polishing compound, rottenstone, or automotive paint polish to put the final gloss on the speaker. Wax it to really make it shine.

 

[Ryan Peddle]

You guys are all so awesome. So far everything is going smoothly. I'm basically doing it very slowly. I live in an apartment and either I am doiing about an hour of work a night, and/or I go to my parents house on the weekend where I have my workshop in their garage where I can spend a few hours on in a contolled environment.

So here is what I have done so far. I had one speaker, the one you see below, primed and painted in black. But man was that not enough. The MDF, like Peg Bundy to Al's wallet, was just sucking life right out of the paint. So I decided to sand it all down and start again.

I used my orbating sander with a 80 grit pad on and that worked well at taking most off. Then I wiped everything down and reapplied woodfiller to all of the teeny tiny spots I could find.

After the wood filler set (overnight) I sanded with 220 grit and then 400 grit pads. Super smooth feel. And then I tack clothed it all down to remove dust and dirt.


Next I prepared a home brew sealant I got out of one of my wood workign magazines. This brew is called Glue Size. The basic formula for glue size is 1 part wood working glue (white or yellow) and 10 parts water. For sealing MDF thought, it is recommended it be a solution of 1 part glue 4 - 5 part water. This stuff works fantastic. Sealed the thing right up. But now the surface was rough again. Back to sanding with 400 grit.

Now with everything all smooth again, I used tack clothe to clean up the surface and I applied 1 coat of primer using a foam roller. I hope to invest in a HVLP paint sprayer, but will do that probably on the next few sets of speakers I build. I'm in no major rush to achieve perfection.

So now I am at the stage of waiting for the primer to dry, then I will sand again, prime again, and see where I am at.

Here are some pics of my progess. Check back for updates.

 

[Ryan Peddle]

Well, I've added an HVLP paint sprayer to my speaker making tools.

I picked up this Campbell Hausfeld turbine unit (HV1016) yesterday . I have yet to use it as I want to set up an area and a table to use it with. Plus I am doing some research on proper usage and technique. But I am really optimistic that I will be achieving my desired finish now.

 

[Greg_R]

Cool! Be sure you get a nozzle / tip that is appropriate for the viscosity of finish that you plan on using...

 

[Greg_R]

Another tip:

I recently puchased a buffer system for wood that is AWESOME for leveling out Poly and paint finishes. I literally wipe the poly onto the wood and then buff it all smooth once the poly dries. You can buy buffers that slip over random orbit sanding discs...

 

[Ryan Peddle]

Thanks Greg, I will definitely look into that.


Here are some updated pics. The first being a very poor, be it piss poor spray job. I had thought I had set up the gun with the proper settings. Boy was I wrong. Time top get sanding.

The second pick is much lighter and smoother.

 

[Jimi C]

What kind of paint did you use? If it was just home depot house paint stuff its probably a little to thick to get a smooth finish. Might want to thin it out with some mineral spirits before respraying. maybe 10:1.

 

[Ryan Peddle]

Hi Jim,

I am using super hi gloss pain from HD. Actually I do thin it out. Maybe not 10:1 but probably 5:1. The paint sprays fine. It was just that I had the sprayer spraying full blast and just caused a lot of drip lines which I try to avoid.

 

[Greg_R]

That type of mistake is known as "orange peel" and is very common with beginning sprayers. TEST and practice spraying 1st! I'd start out by spraying water onto cardboard (as practice). You don't want ANY runs or large droplets. Once you get the technique down, switch over to paint and adjust the nozzle. You want a fine spray that doesn't dry in the air / at the gun tip. TIP: Do NOT use water based paint / latex... use oil based and thin it out. Test the spray on a few scraps before shooting the speaker. It looks like you need more air and less finish...