Home » Sponsored » Pi Speakers » Bmar...can you please explain how to achieve that beautiful finish again?
Bmar...can you please explain how to achieve that beautiful finish again? [message #40982] Mon, 14 April 2003 18:13 Go to next message
gonefishin is currently offline  gonefishin
Messages: 48
Registered: May 2009
Baron
please :)


My speaker project is going quite slow...but we're getting to the point where we will be staining and finishing them soon. Could you please explain (again) what the process is...the more specific you can be...the better. Sometimes I can be thick as a cinder block!


thanks again!

Dan (gonefishin)



enjoy the music!

Ready, Set, Shoot [message #40999 is a reply to message #40982] Tue, 15 April 2003 16:57 Go to previous messageGo to next message
bmar is currently offline  bmar
Messages: 346
Registered: May 2009
Grand Master
Spraying Lacquer

Some ideas to get you started for spraying a finish. You first have to have all your prep work in order. Then choose a good material that will be correct for your application. This summery is for Lacquer and does not take into account the pros and cone of any other types of finish. There are a vast amount of wood finishes available today. Varnish, Shellac, Polyurethanes, Water based, Oils, and Waxes to name a few. We are just going to talk about Lacquer for now since it sprays on easily. Builds and dries fast, and is easy to work with.

First we have preparation. Remember that a clear wood finish will not mask any flaws in the wood. In fact, stains or finish will accentuate the flaw. So a good fit between parts is a must and sanding with the grain using 220 paper helps out. Work your way up to 220 grit in steps. Unless you have some major sanding to do, avoid using 80 grit. Start off with 100 grit, sand again with 150 and then with 220. If you’re using pre-veneered plywood then you should start with 150 grit paper. Random orbit sanders are a great thing but always end your sanding adventure with hand sanding in the direction of the grain with garnet sand paper. Or, better yet, do no sanding and use a scraper.

Now that our cabinet is finish ready we can choose a finish. Sherwin Williams has local stores in all big cities and carries professional wood working products. SW Low-VOC is a good lacquer. I don’t use the water white lacquers because I prefer the amber mellow tone you will get in a few months. If you want a finish that will have virtually no yellowing, use the a water based Lacquer/Varnish/Polyurethane. For the ultimate in amber and mellow ageing tones, use Varnish. I only use Spar Varnish since it is also waterproof and you will never have water damage from a open window, plant or drinking glass. Minwax Helmsman is adequate choice for Spar Varnish. Mohawk, Crystalac, Pianolac, McFadden and Target are some suppliers for quality wood finishes, to name a few.

I use Hood Finishing products, Magna-Shield lacquer. You can look at their products at http://www.hoodfinishing.com. This is a Pre-Catalyzed lacquer that has 40% solids and complete burn in between coats so sanding is not required between coats as with polyurethane or varnish. For added depth use 75% sheen and rub it down to a satin luster. Use a self sealing lacquer because they sand easily. Your first coat will be a sealer and lock the wood fibers down and "pop" the grain. Even with careful sanding some of the wood fibers will be locked in an upright or out of alignment position. This is why after applying the first coat of a finish you will have some fuzzy texture to your project and it will need smoothing.

The better spray gun you can afford the less headache you will have. Having said that, there are a few HLVP conversion guns on the market for $100 that will suit your needs quite nicely. HLVP is a must. The stuff stinks and you don’t want it bouncing all over. More importantly, finish is not cheap and you don’t need to be spraying it all over hells half acres. When your done, Clean your gun.

Good finish techniques that will give you a durable finish as well as a rich look consist of 5 coats and a little elbow grease.

  • Spray sealer coat
  • Wait 1 hour and sand smooth with 220 production trimite paper
  • Spray full wet coat No.2
  • Wait 1 hour
  • Spray full wet coat No3
  • Wait 1 hour
  • Spray full wet coat No.4
  • Wait 24 hours
  • Sand with 220 paper
  • Spray full wet coat No. 5
  • Wait minimum 3 days. (3 weeks would be fantastic)
  • Sand with 400 paper
  • Steel wool using 0000 grade steel wool and use a wool oil
  • Wash off all excess wool oil with damp cloth a few times
  • Paste wax with Johnson's paste wax. Wipe off when hazy


    Now you can sit back and admire your work. I'll talk more about touch ups and repairs another time. If you hanker for an Oil finish, you'll have to consult upon Dr. Epstein since he has some cool tricks for Tung oil, Danish oil, French polish and Shellacs.

    Bill

  • Re: Ready, Set, Shoot [message #41002 is a reply to message #40999] Tue, 15 April 2003 20:15 Go to previous messageGo to next message
    BillEpstein is currently offline  BillEpstein
    Messages: 886
    Registered: May 2009
    Illuminati (2nd Degree)
    I've read shorter Tom Clancy books.
    Allow me to make this a bit longer.
    "Work your way up to 220 grit in steps."
    Veneer comes sanded to about 150, but with defects. Only hand sand with a cork backed wood block using 150 then 220 garnet paper. For a small project like a speaker power sanding isn't necessary. Don't give 3M $4 for that purple stuff. What makes Garnet good is that the abrasive particles break down and won't cause bigger grit scratches. Aluminum Oxide and whatever that purple stuff is will. Your random orbital sander has too soft a pad and will almost certainly create low spots and even sand thru the veneer.
    If you do use a scraper, highly recommended, you still have to sand with 220 after. The scraper burnishes the wood which closes the pores.
    "The better spray gun you can afford the less headache you will have"
    Very true. But for a single project you might want to just go outdoors and spray with spray cans. 2 brands are available from the catalogs, Behlen and Varathane. The latter is by far better.
    In any case, lay the work flat, never spray the vertical if you can help it. Spray north-south in even lines keeping the gun/can the same distance from the work. Don't make an arc. Spray within 6 to 8 inches. Go ahead and really wet the work. Then spray east west the same way. That is one coat.
    Working outdoors is no problem. Lacquer dries to the touch within seconds and dust nibs will sand out from the later coats. Do watch out for the bugs that invariably have to find out what you're doing.
  • Sand with 400 paper
  • Steel wool using 0000 grade steel wool and use a wool oil
  • Wash off all excess wool oil with damp cloth a few times
  • Paste wax with Johnson's paste wax. Wipe off when hazy
  • Wet sand with 400 grit wet or dry, the black paper. Put 2 or 3 drops of dishwashing detergent in a coffee cup of water, dip your fingers and flick some drops on the surface and sand with a hard cork block.
    Go easy. You just want to level the surface, not remove the lacquer you've carefully built up. Watch out for the edges, they never have as much build as the rest.
    "Now you can sit back and admire your work. I'll talk more about touch ups and repairs another time. If you hanker for an Oil finish, you'll have to consult upon Dr. Epstein since he has some cool tricks for Tung oil, Danish oil, French polish and Shellacs."
    Are you scared? Good. Now delete both these posts, get some Boiled Linseed oil or Tung Oil or Watco. Flood the surface, wait an hour, re-wet and wipe off the excess after 20 minutes. Next day another coat same way. Next day 220 grit and even the surface. Apply another lighter coat. Next day sand with 340 stearated (grey paper) and apply a thin coat. Next day 0000 steel wool very lightly with your fingers and wipe on a thin coat. Use Handi-Wipes to apply the oil. Use tack rags after the sanding.
    After this coat Johnsons wax with rag for higher shine or applied with 0000 steel wool for satin finish.
    5 Cabinetmakers, 6 opinions.
    I play Tim to Bill's Al. If you've ever seen his work, you'll know why. Gorgeous.



  • Re: Ready, Set, Shoot [message #41013 is a reply to message #41002] Wed, 16 April 2003 06:02 Go to previous messageGo to next message
    Dr Jekyll is currently offline  Dr Jekyll
    Messages: 3
    Registered: May 2009
    Esquire
    Mr. Hyde,

    Did you know Boiled Linseed oil isn't even boiled? Great stuff and will give you a super finish at a fraction the cost of boutique oil's. Boiled is the same as raw linseed oil with the addition of chemical polymers to aid and speed the drying process. Linseed oil is also one of the most volatile oil's to spontaneously combust when on a rag or cloth. Seriously, The drying rate is accelerated to the point where it absorbs oxygen and builds heat. Always lay out your linseed oil rags flat until they are dry and hard. Balling up the oil soaked rag will surely result in a fire

    Don't be scared, spray away!

    when in doubt use a fine grade wiping polyurethane
    The Horror!

    dJ

    Self immolation and Goopethane [message #41017 is a reply to message #41013] Wed, 16 April 2003 08:08 Go to previous messageGo to next message
    BillEpstein is currently offline  BillEpstein
    Messages: 886
    Registered: May 2009
    Illuminati (2nd Degree)
    Good warning to tyros but old news. Yeah, boiled somehow means heavy metal driers have been added, usually. Behlen and Sutherland Welles do only use heat, however and that is more accurately known as polymerised. Ditto for Tried and True which is 50/50 polymerised Linseed and beeswax which I have commented on before. Great stuff.
    Quick disposal of rages is in a water-filled baggie. The landfill is on fire anyway.LOL!
    Polyurethane? Not on my work!
    Can't fix it, can't remove it and looks like plastic. Not gonna dine or let your kids fingerpaint on your speakers, are you?
    Another however, however. Minwax brand wiping poly is close to the sheen of varnish. Not as plasticky. I did a white oak table top with it a while back and looked good. Needed the protection. Client was going to fingerpaint on it.
    Re: Fine Chris Craft finish [message #41021 is a reply to message #41017] Wed, 16 April 2003 10:57 Go to previous messageGo to next message
    Dr Jekyll is currently offline  Dr Jekyll
    Messages: 3
    Registered: May 2009
    Esquire
    Hey, I like the water filled baggie disposal method for the oil soaked rags. Next time when good speakers go bad, I can just deep six the thing at the curb in a large leaf bag!

    do people actually buy purple sandpaper? the horror. Call up Hood Finishing and get a catalogue. They have all types finishes, stains, sandpaper and supplies. you can buy stuff buy the gallon if you don't need drums and pails.

    My personal favorite if I'm going to brush a finish on is Varnish. Shellac is fun and dries a LOT faster but the varnish is just so nostalgic. I used to use a lot of Zipguard polyurethane years ago. Never see it and don't even know how long it's been gone. The nice thing about Spar Varnish is its made with Tung oil and a lot of other good components in oils. Its weather resistant and has been used on boats, outdoor woodwork, counters and bar tops for years. I like to use on Coffee/End/Dinning tables, bathroom & cucina woodwork, and especially window sills. Minwax makes a semi gloss Helmsman brand that is easy to get and works great.

    I don't think the Helmsman appropriate for the motor yacht,
    But I wouldn't use $85 a gallon Spar Varnish on my window sills either.


    -dJ


    Re: Whoa!!!!!! [message #41024 is a reply to message #41021] Wed, 16 April 2003 12:50 Go to previous messageGo to next message
    BillEpstein is currently offline  BillEpstein
    Messages: 886
    Registered: May 2009
    Illuminati (2nd Degree)
    Magnificent. Yours?
    Re: As fait would have it [message #41026 is a reply to message #41024] Wed, 16 April 2003 13:23 Go to previous messageGo to next message
    Dr Jekyll is currently offline  Dr Jekyll
    Messages: 3
    Registered: May 2009
    Esquire
    I'm afraid, not hardly my dear friend. I have a few more years and a few more line's to tow before I become that Phat.
    Just a prime specimen of spar varnish.
    The Two Bills [message #41034 is a reply to message #40999] Thu, 17 April 2003 06:05 Go to previous message
    gonefishin is currently offline  gonefishin
    Messages: 48
    Registered: May 2009
    Baron
    Thanks ever so much for all your help...again!

    hmm...I think I may just attach that woodworking 101 thread here...and I'll have myself a nice little FAQ.

    thanks!!!!!!!!!!!!!!


    :D


    enjoy the music!

    Previous Topic: Group Delay Calculation Formula
    Next Topic: Linn
    Goto Forum:
      


    Current Time: Wed Aug 14 22:31:57 CDT 2024

    Sponsoring Organizations

    DIY Audio Projects
    DIY Audio Projects
    OddWatt Audio
    OddWatt Audio
    Pi Speakers
    Pi Speakers
    Prosound Shootout
    Prosound Shootout
    Miller Audio
    Miller Audio
    Tubes For Amps
    TubesForAmps.com

    Lone Star Audiofest