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Discussion Starter · #1 ·
I have spent some time reading about all the great finishes out there and I figured a thread dedicated to DIY painting would be good.


What equipment should be purchased? I have looked online, went to HD and Lowes and it seems like there is a large cost required for professional products. The compressors needed are all in the $400+ range then the guns are $100+. If Im not going to use it constantly I does seem like a good investment.


IF not pro grade equipment, then what? Spray cans? Is there something a little better that allows for a better spray coat from a rookie? Maybe its just practice and techinque.


Primer/base coats on MDF? What is the best?


Bondo/body filler, what are the best options? How do we make it smooth?


Sanding? How many coats, what should we buy to make a paino gloss black finish.


Clear coats? Poly? Do we do this when we paint to get a high gloss protected finish?


Waxing?
 

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Unless you have a compresor that can put out 8-10cfm at least, forget about painting, you will most likely have poor results. My Sata NR2000 HVLP spray gun uses about 13 cu ft / minute.


Unless you already have a use for an air compresor, and it's a decent size, the amount of $$ to get in is prohibitive for most people.


I have had generally good results in painting MDF, however the one enclosure that I painted and took to Indianapolis developed glue lines during the trip down. ( moisture change )


It seems like you have to seal the MDF really well both inside and out and make sure it's very close to the humidity that it will 'live' in. Nick McKinney posted to use a west system epoxy if you want the best results, coat the entire enclosure on the outside, sand smooth, prime and paint.


I have used inexpensive Minwax urethane to seal MDF, generally 2-3 coats with dry time in between both inside and out of the box. The sanded urethane finish will keep your primer from soaking into the MDF much.


A spray can of good quality paint ( think auto paint from a jobber ) will give you good results on a sealed finish, and they are up here, about $ 20 per can for a custom mix. Not the toughest finish compared to a cross linked polyurethane, but also not as bad for you. ( catalysts contain Isocyanates )


You need proper protective gear when dealing with the strong solvents, and especially with isocyanates. There are paint systems that do not use any isocyanates, especially those for cabinet finishing.


Body filler works fine on MDF, I use a sanding block to get it flat. 180 grit paper is fine for primer, too coarse and you will have sandscratch showing.


Clear coats: there are many types and chemistries, it's best to use compatable products from a single company to assure that you will have no problems. Some products have a maximum thickness, like the catalyzed lacquer I have sprayed.


Bottom line: talk to a paint professional before you shell out any $ on what to use. Ask people that have used their product before.
 

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Not being as picky as most here with my finish, I just brush painted some semi gloss black on my sub box and it looks decent. I wouldn't want to sell a product like this, but it looks pretty good.


Harbor freight has the guns for spraying, but I have read the quality is sub par. They start at around $15 for their guns.
 

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Quote:
Originally Posted by brandonnash /forum/post/16940713


Not being as picky as most here with my finish, I just brush painted some semi gloss black on my sub box and it looks decent. I wouldn't want to sell a product like this, but it looks pretty good.


Harbor freight has the guns for spraying, but I have read the quality is sub par. They start at around $15 for their guns.

I used a cheap touch up sprayer from Harbor Freight to spray the poly onto my curved E-wave speakers. With a little care it did a great job. Make sure to practice on some scrap wood pieces first though!!
 

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I know the HD around me rents stuff out, haven't ever checked on renting a compressor/paint setup, but if you're spraying a bunch of cabinets and only really need to do it one time, might be worthwhile to check out rental rates.
 

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Discussion Starter · #6 ·

Quote:
Originally Posted by michael hurd /forum/post/16940423


Unless you have a compresor that can put out 8-10cfm at least, forget about painting, you will most likely have poor results. My Sata NR2000 HVLP spray gun uses about 13 cu ft / minute.


Unless you already have a use for an air compresor, and it's a decent size, the amount of $$ to get in is prohibitive for most people.


I have had generally good results in painting MDF, however the one enclosure that I painted and took to Indianapolis developed glue lines during the trip down. ( moisture change )


It seems like you have to seal the MDF really well both inside and out and make sure it's very close to the humidity that it will 'live' in. Nick McKinney posted to use a west system epoxy if you want the best results, coat the entire enclosure on the outside, sand smooth, prime and paint.


I have used inexpensive Minwax urethane to seal MDF, generally 2-3 coats with dry time in between both inside and out of the box. The sanded urethane finish will keep your primer from soaking into the MDF much.


A spray can of good quality paint ( think auto paint from a jobber ) will give you good results on a sealed finish, and they are up here, about $ 20 per can for a custom mix. Not the toughest finish compared to a cross linked polyurethane, but also not as bad for you. ( catalysts contain Isocyanates )


You need proper protective gear when dealing with the strong solvents, and especially with isocyanates. There are paint systems that do not use any isocyanates, especially those for cabinet finishing.


Body filler works fine on MDF, I use a sanding block to get it flat. 180 grit paper is fine for primer, too coarse and you will have sandscratch showing.


Clear coats: there are many types and chemistries, it's best to use compatable products from a single company to assure that you will have no problems. Some products have a maximum thickness, like the catalyzed lacquer I have sprayed.


Bottom line: talk to a paint professional before you shell out any $ on what to use. Ask people that have used their product before.

Thanks Michael!!
 

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Those cheap guns at harbor freight are pretty much one use and that's it. If you want a good gun that you can use over and over you have to spend in the region of $200 or so. Those can be taken apart with ease and cleaned.
 

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Michael is spot on in his assessment...(sounds like you have some experience)

I had painted cars for 15 years before I went into the office...and I would prefer the auto finishes out there, since that is what I had been trained in, with the caveat that you protect yourself...(shoot suit and fresh air...Iso's can get in to your system almost anyway, but they LOVE mucus membranes!)

I have been hovering for a while, and am really thinking of taking the plunge into DIY...(thanks to you guys, of course). Anything I do will be ultra high gloss black...for myself, it would have to be perfect.

I would take Michael's work a step further, bondo/poly putty, prime, and finish with 320g. Then guidecoat, and wetsand w/ 500g. Base/ 2 coats Clear...wetsand with 1200// 2 more coats clear...wetsand w/no less than 2000g nicken...buff and polish.

So deep you can shave in it!


I kow it sounds easy, but am skipping significant steps here...I can walk anybody through it if they are interested...
 

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Quote:
Originally Posted by kevin g. /forum/post/16943621


I know it sounds easy, but I am skipping significant steps here...I can walk anybody through it if they are interested...

What about that sounds easy, I am exhausted just reading your post



For the amount of time and money invested to do a proper paint job it seems more cost effective to hire someone to do it. If I had facilities like you Kevin then that would be a different story.


I did take a snap shot of the last time I painted though
 

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If you want easy, forget gloss black.
Brandon and Zaph turn out some good looking stuff with textured paint in a rattle can. Duplicolor and Rustoleum are two brands that work pretty well.
 

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Discussion Starter · #12 ·

Quote:
Originally Posted by catapult /forum/post/16944155


If you want easy, forget gloss black.
Brandon and Zaph turn out some good looking stuff with textured paint in a rattle can. Duplicolor and Rustoleum are two brands that work pretty well.

Well thats the whole point of this thread....I do not want to forget about gloss black



I would just veneer if I was to forget about high end paint finishes and that is what I have done for awhile now.


I just wanted to have a thread to discuss how to do a high end finish. Step by step would be awesome. Maybe others could use the expert advice in the thread too.
 

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Discussion Starter · #13 ·

Quote:
Originally Posted by kevin g. /forum/post/16943621


Michael is spot on in his assessment...(sounds like you have some experience)

I had painted cars for 15 years before I went into the office...and I would prefer the auto finishes out there, since that is what I had been trained in, with the caveat that you protect yourself...(shoot suit and fresh air...Iso's can get in to your system almost anyway, but they LOVE mucus membranes!)

I have been hovering for a while, and am really thinking of taking the plunge into DIY...(thanks to you guys, of course). Anything I do will be ultra high gloss black...for myself, it would have to be perfect.

I would take Michael's work a step further, bondo/poly putty, prime, and finish with 320g. Then guidecoat, and wetsand w/ 500g. Base/ 2 coats Clear...wetsand with 1200// 2 more coats clear...wetsand w/no less than 2000g nicken...buff and polish.

So deep you can shave in it!


I kow it sounds easy, but am skipping significant steps here...I can walk anybody through it if they are interested...

Thanks!


I would love to see a nice break down with actual product choices and kind of a dummies guide....like what is Guidecoat? and 2000g nicken ?


I have a local connection for possibly getting my project professionally done but I still would like to try it on my own.


I havent researched the rental option yet and I do not have the proper ventilated area to do this either so that might be a huge road block.
 

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That would be no trouble at all. If we can swap expertise...that would be even better for me, as I have seen your work penngray, and have been very impressed. (once you learn my trade...there are no more secrets to behold...
)

Quick questions answered: Guide coat is just a quick blast of spray-bomb over your primer...(sometimes even helpful in your bondo work), you spray a light coat before each successive sanding step...as you sand, any of the color left behind either shows low spots or sand scratches from previous grits. For example: say, you have your bondo work completed finished in 80 or 120 g, you spray your first coats of build primer, when it is cured, you lightly spray a coat of black spray-bomb...kind of speckling the entire surface...you will then use a board with a finer grit sandpaper than you finished the bondo with...220 or 240.(the same idea you use when finishing wood for staining I'm sure). Block sand the entire primed surface in a criss-cross pattern and you will see the low and heavier sand scratch spots jump out...the speckled areas will still be there and you will see the flat areas have a nice sanded smooth look. Continue sanding until you either break through the primer/bondo, or the low spots/scratches come out.

Nicken is just a type of coated sandpaper, Meguiar's makes the best wetsanding paper on the market, IMHO...
 

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Zinser BIN is the ticket for sealing up the MDF after you sand it smooth and do any bondo work on it. After that you can hit it with a good catalyzed primer and move on from there without worrying about those damn glue lines peeking through your work.


I finished these stands a couple months ago and have yet to see any ill effects after some drastic humidity variations this summer:
 

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Having shot a few cars I have no urge to shoot my boxes. While a little more labor intensive I've rolled a couple gloss black boxes with good results.


As they said you need to seal the MDF, if thats what you're using. I've seen titebond and water used with good results. Seal and sand mostly smooth to 220 grit. I've been using kilz oil based primer since its cheap, works very well and is readily available. Two thin coats of primer and then sand to 220 grit. 3 coats of a quality, oil based gloss black and then wet sand all the way to 1000 grit. I've been using rubbing and polishing compounds to bring the super shiny gloss out. At this point you can leave it here or apply 2-3 coats of acrylic clear coat. I use acrylic since it doesn't yellow like poly based clear coats. Again wet sand to at least 1000 grit followed by rubbing and polishing compounds.


A couple of things I've learned along the way. Use nice rollers. If you are forced to get cheap rollers spend extra time cleaning them. If you don't clean your rollers you'll end up with little hairs stuck in the paint which are a real pain to sand out. The best method I've found to clean the rollers is to mount them on the roller handle and spin them with about 40 psi of air from your compressor. Do it outside since it will make a mess.


While I generally don't like the foam rollers they seem to work better than cheap nap style. You don't need to clean them beforehand and they won't leave little hairs in your paint. The oil based paint seems to spread just as evenly on properly prepared surfaces so I see no reason to avoid them.


I've never been able to get a water based black paint to smooth out the way that oil based does. Even with lots of elbow grease it still comes out poorly. Its why I put up with the stink of oil based.


If you're going to do any kind of corner treatment on an MDF box be sure to apply wood hardener to all corners beforehand. I've noticed while chamfering edges the MDF will spread the tiniest bit which means you have to putty/bondo it before you paint or you end up with wrinkles on all your edges.


If you've never used rubbing or polishing compound before, look it up before you try it. If you don't do it right they can have mediocre or even ill effects. I have two 7" buffers with lambs wool bonnets and I get much better results using papertowels by hand. Some people swear by the special terry cloth towels but I didn't see any difference in my test. You can get the compounds as cheaply as $2 each at walmart so its well worth a try.
 

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Ventoso,

Very nice indeed...I am not familiar with "glue lines", having only worked with painting mdf very little...I had repaired a box that somebody attempted to build/finish for a friend a few years back...will post pics when I get home. But I have not seen the box since.


LHD21,

Agreed, automotive-style is not for the faint of heart, but it is very durable, and beautiful, and as I stated earlier, it is my chosen method, as I have had literally shot hundreds of cars, so it kinda comes natural....

Also Agreed, there is definitely an art form to buffing/polishing...
 

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Quote:
Originally Posted by kevin g. /forum/post/16947037


LHD21,

Agreed, automotive-style is not for the faint of heart, but it is very durable, and beautiful, and as I stated earlier, it is my chosen method, as I have had literally shot hundreds of cars, so it kinda comes natural....

Also Agreed, there is definitely an art form to buffing/polishing...

I'd honestly prefer to shoot but I have serious concerns about the impact to long term health. I've never found a respirator that kept me from getting paint boogers and it just bothers me. I've tried at least 6 different types and none of them were cheap.


If you have the ability to shoot, do it. If you do it right its a quality finish thats hard to beat.
 

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Quote:
Originally Posted by penngray /forum/post/16946328


I would love to see a nice break down with actual product choices and kind of a dummies guide....like what is Guidecoat? and 2000g nicken ?

.

Didn't somebody have a thread similar to that last year? Was it member Kouack? I'm wanting to say that it was...
 

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Something I know about " Finally " !.


Are you looking for piano gloss black high luster durable finish ?


A quality finish is dependent on several factors , the most important


is Prep work , done else where from where you'll spraying the finished product .


Making a plastic " CLEAN ROOM " enclosure , with a small exhaust fan


is nearly essential , unless you wish to waste a lot of material by sanding


lint and airborne particles out of the material prior too buffing it !.


Keeping everything including your clothes ( use a treated paper chemical suit or TOP Quality painting suit ) clean floor damp not wet just damp booties on shoes spray one unit at a time minimizes over spray and extra work for you .


You tell me what finish you want to have and I'll recommend the Best


Material for the job .


FYI ; I've formulated coatings for 3 of the largest company's in the world as well as actually applied them. From aircraft, spaceships ,automotive ,marine and commercial Sound manufactures for nearly 4 decades now .


I made carbon fiber " White " Hollywood Bowl sound system attested too that fact !.


Think polyester/ polyester urethane / Urethane / and if you want to level and buff or finished spray as it lays .
 
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