Neck (Re-)Finishing information

Discussion in 'Luthier's Corner' started by Groovecenter, Dec 19, 2003.

  1. I just got back from college, and realized how bad my house is in terms of varying temperatures. Where I keep my basses it goes from probably under 50 to about 70 degrees. I live in Brooklyn, NY BTW, so temps between seasons can vary bigtime as well.

    I have a warmoth bass I finished myself using Nitro Cellulose from Stew Mac. The neck on my warmoth moves alot with temperature, and that kills me, as Im a person who sets up his instrument to have very little relief and low action.

    I have heard that Nitro is not a very good finish when it comes to limiting movement within the wood, and that something like a poly based finish would work better and be harder. My question is, is there a finish that would provide better protection from varying temperatures or atleast prevent the effects of wood movement better than the thin Nitro I used?

    Also, would I be able to apply this finish over the nitro, or would I need to sand it completely, strip it, or just rough sand it to give it teeth for a new application of finish.

    By the way, I am not looking for advice like "Just keep you're instrument somewhere where temperatures vary less." No such place exists in my house; it is a very old, very drafty Victorian. I'm just looking to refinish the neck in something that would provide better protection, not absolute protection; I understand wood moves and will always move, Im just seeking to lessen that effect.
  2. Woodboy


    Jun 9, 2003
    St. Louis, MO
    In order to achieve what you are after, you'd have to encase the entire neck in a waterproof finish. Epoxy or Spar varnish come to mind. That means fingerboard, truss rod slot, tuner holes drilled in the neck. As you can see, to waterproof the neck will be next to impossible. Water vapor will find it's way into the wood to reach what is called Equilibrium Moisture Content. Temperature doesn't affect wood all that much. As the temperature rises and falls, the relative humidity of the air rises and falls and this is what causes wood movement. I am surprised that your neck is so unstable. I am assuming flat-sawn maple for the neck, but what is the fingerboard made of?
  3. Fingerboard is Pau-ferro, and it's not that the neck is that unstable, it's that the temperatures in that room and my house are that unstable. You would be amazed at how cold than hot my house can be.

    Also to be considered is the fact that I don't want a completely moisture and water proof seal, just something better than nitro cellulose. I've heard Carey Nordstrand talk about how the poly's he uses on his basses provide much more protection than a thin lacquer like Nitro.

    Thanks for the response.
  4. Well Groovy, you've asked for suggestions while limiting your options at the same time. With these parameters, nothing I know of will do exactly what you want.

    With Nitro as the base coat, there isn't anything other than nitro that can be put on top without complete removal of the lacquer. The lacquer is one of the hardest finishes known - but it's thin compared to a high solids finish like clear polyurethane. I think the protection that Nordstrand refers to is the impact protection that poly gives over nitro. Though hard, nitro is quite brittle.

    Woodboy has offered the solution to your problem. It's the moisture that makes the neck move. Controlling the humidity in your home is the easiest and surest way to cure this. You can do this as simply as using a dehumidifier to take moisture out or a pot of steaming water to put moisture in.
  5. I did in fact gloss over the response without reading it thoroughly enough. I know this is probably pretty elementary to you guys, but hey, I have to learn somewhere. Im just going to sort of bullet point what I've pulled from the posts. please correct as necessary.

    Both poly and nitro both offer the same degree of hardness and moisture (or lack of moisture) protection, with poly just offering greater impact protection and less brittle of a surface.

    Temperature (with the exception of extreme cold or heat) does not truly effect wood, it is the moisture content of the wood.

    By adding a humidifier to the room, I will reduce wood movement within the necks of my basses.

    Once again, I know this is simple stuff for you guys, but unfortunatly for me, most bass knowledge is a posteriori. Thanks for the help.

    Big thanks to woodboy and Hambone for the imparted knowledge. :)
  6. FBB Custom

    FBB Custom TalkBass Pro Commercial User

    Jan 26, 2002
    Owner: FBB Bass Works
    What you want is to maintain a constant humidity throughout the year. In New England Winters, relative humidity indoors can plunge down into the 20's, while in the summer, it can soar into the 90's. I read somewhere that the national average is about 42%. People seem to have the most trouble in the winter when it gets extremely dry, so you will probably want a humidifier/dehumidifier, if you can manage that. That will work year round to help you maintain a consistent environment.

    This is actually a common problem for people with older steel strings that have no truss rod or stable reinforcement in their acoustic guitar necks. Imagine if you couldn't even tweak the setup!
  7. bwbass


    May 6, 2002
    While nitro is a great finish, I would dispute the assertion that it offers identical moisture protection to poly finishes. You can even steam dents out of wood through nitro if you're patient enough!

    And the most "stable" finish on a maple/pau ferro neck would be one that limits the rate of moisture absorption of the maple to that of the pau ferro, which is normally lower. As long as the neck and fingerboard woods are taking on and losing moisture at the same rate the neck shouldn't move that much. That being said maintaning a more constant humidity in your house will be easier to do!
  8. Thanks again for the responses. It looks like Im going to be setting up in a more stable room (my own). Thanks for all the replies.

    As for the humidifier/dehumidifier, Im going to be looking for a small, low priced one, as the room it would be inhabiting is quite small.