DIY stabilized wood experiment

Discussion in 'Luthier's Corner' started by Hambone, May 7, 2004.

  1. OK, we know all about the stabilized wood products out there like Dymondwood, Rockwood, and any number of other brands and processes. I've been intriqued by these materials since about 1967 when my father (a craftsman in his own right) carved a set of candle sticks for the altar of a large church using a material called "NovaWood". This was the grandfather of the modern stabilized woods. Novawood was resin impregnated hardwoods that were then bombarded with gamma rays to alter the molecular structure of the wood. Each candle stick was about 2 feet tall and weighed in at around 20 lbs apiece. They still sit on the altar at that church and I expect they'll be there for the next 1000 years or so.

    Hey, where's the fun without a good story? :p

    At any rate, I've done an experiment using clear red cedar, walnut, maple and MDF. I cut small pieces and sealed them in a container filled with Minwax Wood Hardener. This is a clear, resin product designed to be used on soft or rotten wood to harden it and make it ready for paint. It's a pretty aggressive solvent based resin that soaks in, hardens and then can be sanded or painted.

    As I surmised before the test, the maple and walnut weren't porous enough to soak up much resin. They looked great on the exterior but inside, they weren't impregnated. BUT the cedar and the MDF were another story. The cedar soaked up the resin pretty good and made it much harder than original. I sliced through my sample piece and found that although the resin had soaked deep, it hadn't made it all the way to the core of my piece. The MDF was the best of all though. When it went into the resin bath, it began bubbling and foaming as the air inside the MDF escaped and was replaced by the resin. It was a lot of fun to watch. I let the samples sit for 48 hours before testing the results. The MDF came out solid and firm. It was darker (expected) but was about 4 times harder than the raw stock. Sanding it was easy and it created a heavier dust than before. I think it would be very easy to route or drill. My main idea was to use blocks of this as the returns on pickup covers. Route and sand the perimeter and cavity, glue a piece of nice presentation wood veneer to the top and paint the sides. It's gonna work great.
  2. mnemonix


    Apr 27, 2004
    I'm surprised they didn't glow in the dark ! ;)
  3. Or turn into the Hulk when they got mad....

    Hey, try this: vaccuum chamber with the same test. I bet the vaccuum would open the pores and force the resin in deeper and more intensly.

    Werd up.
  4. Tim Barber

    Tim Barber Commercial User

    Apr 28, 2003
    Serenity Valley
    Owner: Barber Music
    Very cool, Hambone :) The Minwax stuff works great on MDF, although I have not tried soaking, just liberal brushing. I use it on my routing templates. The pic is a control cavity template; the drop-in ring is MDF and the main piece is basswood, also hardened with Minwax. I have a body in progress made of douglas fir with a walnut top; I was thinking of giving the fir a good soak to toughen it up.

    The Minwax apparently exerts some appreciable pore pressure, though. I tried it on one side of a piece of soft spalted maple and it actually arched the wood so much it split :eek: Should have treated both sides.

    BTW what was the thickness of your test pieces? It would be interesting to do a batch of several identically-sized pieces, and pull them out at, say, one-hour intervals. You could then graph the time vs. depth of penetration for different materials.
  5. Hey, I do exactly the same thing on my templates - You didn't steal that idea from me did you? [dialing attorney] ;)

    My pieces were ¾" square and about 3" long to fit my glass jar for soaking. I can tell you that the harder woods wouldn't show anything after an hour except surface hardening. In fact, the MDF didn't stop bubbling for several hours after immersion.

    I like Mon's suggestion. It sorta brings the DIY aspect up closer to how the real stuff is made. How would you do a simple test setup to try the idea? Could I just fashion an adaptor to the top of my jar and use my 5 HP vacuum to suck the air? Sorry, my vacuum experience is limited to vacuum tables used in graphic arts.

    I wonder if I could fashion a vacuum bag that wouldn't react with the resin so that I could put larger pieces in it but only use a small amount of resin. Keeping the air out is important with this stuff because it'll dry on you fairly quickly. I'm thinking like stabilizing some laminates or veneers like this.
  6. I was thinking adapting the idea of them handy food sealer vaccuum units. I see them relatively cheap, they claim to have a "comercial grade" vaccuum, and the bags they use can be cut to any could potentially do multiple materials at once... the biggie being chem reactions, and set-up times for the resin in fast does this stuff kick?

    I'm thinking the vaccuum to accelerate the capillary properties in the wood pores, and sorta really forcing the stuff in.

    Just a thought.
  7. Tim Barber

    Tim Barber Commercial User

    Apr 28, 2003
    Serenity Valley
    Owner: Barber Music
    It's entirely spies are everywhere. Unfortunately the file containing that specific information has been accidentally set on fire and is not available. This is the subject of an ongoing internal investigation and I am not at liberty to disclose the contents of those documents, which, although they have been destroyed, never in fact existed in the first place. The persons responsible have been sacked.
  8. Timmy B for Congress!!
  9. would ash be a good material for the treatment, seeing as it's so porous?
  10. I would think the pores would certainly be filled but the wood between them wouldn't soak up much of the resin. That's some tough stuff there.
  11. ubersam


    Oct 12, 2000
    Just curious, what do you all think would happen if I brushed some of that Minwax stuff onto a mahogany body that has been previously oil finished? Would the body retain it's tonal quality? Would the surface still feel like oil finished wood? Would the surface be hard enough that it would be hard to ding or gauge?

  12. My inclination is that it could be a mess. The Minwax has lots of solvent and a very hard drying resin. The solvent helps with the absorption and I'm afraid that the solvent would really loosen the oil, mix with the resin and then who knows what that would gel into. You can do a harder surface like a lacquer or a poly right over an older oil finish without problem. That would increase it's resistance to scratching. But in my mind, the only practical way to increase it's ding factor is to really put a thick hard finish over it. Sure, it could change the tone, but you can't have everything when dealing with natural materials. The trick is to guess ahead and predict a tone change that you can fall in love with. I don't have that touch (maybe one day)
  13. ubersam


    Oct 12, 2000
    I guess I wouldn't be experimenting anytime soon. This is my first oil finished bass and I'm really digging every aspect of it, right down to the feel of the wood.
  14. You might also want to look into a product called CPES made by Smith and Co... It's an extremely low viscosity two part epoxy designed for high penetration; cures rock hard and looks gorgeous. Used in architectural settings for rotten wood restoration and used all over in boats for wood protection.

    i don't know the Minwax stuff taht well but if it's a one part (rather than a two part) product it seems like it would cure differently.
  15. I think you're right about the cure type. The minwax stuff will be solvent drying while your epoxy would be catalyst cured. The minwax won't really cure until removed from the solution and dried. Epoxy would cure IN the wood very quickly. That might be the real advantage. Thanx
  16. adolganov


    Jan 15, 2004
    I have a suggestion: you can dip your wood in the solvent first to open the grain some more dissolving the resin to increase the penetration. And maybe heat the wood before soaking in the hardener...

    I am on the way of replacing the fingerboard for my fretless and already got one very funky looking peace of rosewood. To be able to use the roundwounds, I plan to harden it with the similar product after the radiusing so the low penetration hopefully wouldn't be an issue .
  17. Hmmm.

    This is really interesting.

    1. Douglas Fir for a bass body? Isn't it a bit soft? I con understand the hardening part, but can the wood be hardened enough? Unless you're just using it on the wings.

    2. Isn't it part of the whole myth & legends that wood with open pores resonates better? I thought I've read that several times around here.

    3. A friend of mine works at a high tech testing lab. I'll ask him if I can get something put in under high vacuum. I'm not sure if more vacuum is better, but it would be interesting to see.

    4. What about pressure treated lumber? Anybody use that, at all and in any way, in building a bass? Just curious. I was goofing off at a local Home Depot and the idea kinda came to me.

    Really interesting discussion.