the force from the expansion can't be beaten by any glue, unless if you want to throw bows with that guitar... search for a kind of aluminum with less expansion
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Bonding aluminum to wood.
- Thread starter Benjamin Strange
- Start date
There is no doubt you need a piece of hard aluminum if you plan to use steel strings, but it's not as simple as it sounds.
Unless you have plenty of money and the time to find a place which actually does mil-spec hard anodizing and not some shallow surface hot dye process claimed to be hard anodizing, and once the right shop is found, convincing them to do a single piece run for anything less than a batch run price will simply not happen. There are other considerations with hard anodizing, including the "growth" of your parts. Hard anodizing adds to the surface so all your dimensions will be larger after the anodizing is complete. If the hardening is deep enough to make it worth doing, you will either have oversized parts or will need to supply your plating contractor with parts cut to the correct undersized dimensions to come out with a part which meets your dimensional spec. This is not a hard and fast adjustment so it's usual for several different test pieces to be done before the right combination of undersize parts and bath time is determined to produce the desired finished dimension. One other thing to consider regards true hard anodizing is color, and I'm not talking about red, yellow, or green, I'm talking about dark olive or dull slate gray/green, both of which are decidedly flat (non reflective) in appearance and present a surface texture much like bead blasted raw aluminum. It will not be slick at all and there is in fact a noticeable drag if you lightly pull your finger across the surface. I've never had occasion to try polishing a hard anodized surface, although I'm sure it could be done, but it's harder than chinese algebra so be prepared for long slow going at the wheel if you decide to give it a spin.
You would be better off (cheaper) buying an oversized aluminum forging and contracting a local machine shop to cut it down to the required dimensions. If you go the forging route, plan your cuts so the first one is to the playing surface and is the absolute minimum required to get the desired radius, then bring the rest of the slab to size using the center of that radius as your reference for both length and width. Forging hardens metal, but unless the piece is thin (usually less than .250") it's not hard through and through like a heat treatment, but it's generally deep enough to take shallow cuts without getting into the gooey center. Make sure you pick a good machine shop with experience milling forged aluminum because timid cutting on aluminum forgings can be disaster as the upset portion tends to work harden when milled. A single hogging pass with a slow, light finish cut is preferable and much more accurate than multiple shallow passes made in an attempt to avoid overcutting. Multiple passes quickly turn into a vicious cycle where the surface gets harder on every pass, so feed and speed will have to be reduced every pass or chatter marks get deeper and before you know it the piece goes from useful widget to really nice doorstop status. One last thing to consider on machining a forging. In order to make a single hogging pass which produces a radius is going to require a tool with the radius ground into it. If your machine shop is not capable of grinding their own tools this means adding the cost of a new tool and the bill for a special grind to your budget.
Heat treating is another way to get a hard piece of aluminum, but if you heat treat post process you stand a good chance of having an out of tolerance piece due to material upset from the heat treat. on larger pieces you can build fixturing to hold your part(s) so they can't creep during the treating process, but this can, and usually does, result in uneven treatment leaving you with soft spots near, or under where the clamping devices were located. I have made batch runs of small parts where the material was heat treated prior to machining to avoid stupid high reject rates due to the inherent dimensional upset which occurs when small nonferrous parts are put through a heat treat process, but have a hefty tooling budget and allow almost twice the cycle time as you would for the same untreated material if you go this route.
Last of all, and IMHO most practical if you want a long lasting metal fretboard that doesn't weigh as much as the rest of the instrument, would be to fashion one from aluminum (to save weight) and get it metal sprayed with low carbon content steel, titanium, or any other rust resistant material harder than the strings you plan to use. It would still be tricky because you would need to undersize any surface to be sprayed by an RCH, and you would still want the sprayed surfaces to be a bit proud so you could hand finish them to soften corners and such. In short, to avoid cutting into your base material when finishing, you will need an undersized base and an oversized spray. Do some looking for Jet Hot coatings if you are interested in more detailed info on this process.
It could be done, but just making an aluminum slab both hard enough to last and also ready to glue/affix is going to be a real job in and of itself. Not impossible, but certainly not a walk in the park, or cheap. It would truly fall into the labor of love category.
Another alternative which would be (relatively speaking), cheap and easy would be to simply carve an aluminum slab from 7075, mount it mechanically and make it easy to remove, then replace as needed.
As for gluing, I would look at any and all alternatives first due to the unequal expansion/contraction rates between wood/glue/aluminum. A non hardening glue might be the ticket, but I'd still be afraid of it for a while before I'd trust it to not fall off if exposed to sudden or extreme temperature change.
Last of all, alodine is strictly a corrosion treatment and while it offers a light etch, is only compatible with a very narrow range of paints and adhesives. Bostic brand poly over a zinc chromate base is the only thing I've ever seen that will really hang in there over your typical alodine prep.
Unless you have plenty of money and the time to find a place which actually does mil-spec hard anodizing and not some shallow surface hot dye process claimed to be hard anodizing, and once the right shop is found, convincing them to do a single piece run for anything less than a batch run price will simply not happen. There are other considerations with hard anodizing, including the "growth" of your parts. Hard anodizing adds to the surface so all your dimensions will be larger after the anodizing is complete. If the hardening is deep enough to make it worth doing, you will either have oversized parts or will need to supply your plating contractor with parts cut to the correct undersized dimensions to come out with a part which meets your dimensional spec. This is not a hard and fast adjustment so it's usual for several different test pieces to be done before the right combination of undersize parts and bath time is determined to produce the desired finished dimension. One other thing to consider regards true hard anodizing is color, and I'm not talking about red, yellow, or green, I'm talking about dark olive or dull slate gray/green, both of which are decidedly flat (non reflective) in appearance and present a surface texture much like bead blasted raw aluminum. It will not be slick at all and there is in fact a noticeable drag if you lightly pull your finger across the surface. I've never had occasion to try polishing a hard anodized surface, although I'm sure it could be done, but it's harder than chinese algebra so be prepared for long slow going at the wheel if you decide to give it a spin.
You would be better off (cheaper) buying an oversized aluminum forging and contracting a local machine shop to cut it down to the required dimensions. If you go the forging route, plan your cuts so the first one is to the playing surface and is the absolute minimum required to get the desired radius, then bring the rest of the slab to size using the center of that radius as your reference for both length and width. Forging hardens metal, but unless the piece is thin (usually less than .250") it's not hard through and through like a heat treatment, but it's generally deep enough to take shallow cuts without getting into the gooey center. Make sure you pick a good machine shop with experience milling forged aluminum because timid cutting on aluminum forgings can be disaster as the upset portion tends to work harden when milled. A single hogging pass with a slow, light finish cut is preferable and much more accurate than multiple shallow passes made in an attempt to avoid overcutting. Multiple passes quickly turn into a vicious cycle where the surface gets harder on every pass, so feed and speed will have to be reduced every pass or chatter marks get deeper and before you know it the piece goes from useful widget to really nice doorstop status. One last thing to consider on machining a forging. In order to make a single hogging pass which produces a radius is going to require a tool with the radius ground into it. If your machine shop is not capable of grinding their own tools this means adding the cost of a new tool and the bill for a special grind to your budget.
Heat treating is another way to get a hard piece of aluminum, but if you heat treat post process you stand a good chance of having an out of tolerance piece due to material upset from the heat treat. on larger pieces you can build fixturing to hold your part(s) so they can't creep during the treating process, but this can, and usually does, result in uneven treatment leaving you with soft spots near, or under where the clamping devices were located. I have made batch runs of small parts where the material was heat treated prior to machining to avoid stupid high reject rates due to the inherent dimensional upset which occurs when small nonferrous parts are put through a heat treat process, but have a hefty tooling budget and allow almost twice the cycle time as you would for the same untreated material if you go this route.
Last of all, and IMHO most practical if you want a long lasting metal fretboard that doesn't weigh as much as the rest of the instrument, would be to fashion one from aluminum (to save weight) and get it metal sprayed with low carbon content steel, titanium, or any other rust resistant material harder than the strings you plan to use. It would still be tricky because you would need to undersize any surface to be sprayed by an RCH, and you would still want the sprayed surfaces to be a bit proud so you could hand finish them to soften corners and such. In short, to avoid cutting into your base material when finishing, you will need an undersized base and an oversized spray. Do some looking for Jet Hot coatings if you are interested in more detailed info on this process.
It could be done, but just making an aluminum slab both hard enough to last and also ready to glue/affix is going to be a real job in and of itself. Not impossible, but certainly not a walk in the park, or cheap. It would truly fall into the labor of love category.
Another alternative which would be (relatively speaking), cheap and easy would be to simply carve an aluminum slab from 7075, mount it mechanically and make it easy to remove, then replace as needed.
As for gluing, I would look at any and all alternatives first due to the unequal expansion/contraction rates between wood/glue/aluminum. A non hardening glue might be the ticket, but I'd still be afraid of it for a while before I'd trust it to not fall off if exposed to sudden or extreme temperature change.
Last of all, alodine is strictly a corrosion treatment and while it offers a light etch, is only compatible with a very narrow range of paints and adhesives. Bostic brand poly over a zinc chromate base is the only thing I've ever seen that will really hang in there over your typical alodine prep.
Odd... I never had any problems with my Kramer... but that was long ago... so very long... It's hard to remember...
Me, in 1979, playing a house party on my Kramer 6000:
Link Removed
In your position, I would grind it flat and parallel (level), hard anodize it, and forgo the setup on the pretensioning jig. For one thing, you're intending to put a heck of a lot of maple there. Secondly, fretless basses normally have some relief, so why not a guitar?
That is, with the preceding assumption that you find an adhesive that likes the anodizing. Have you tried Henckel's site? they have an adhesive picker that lets you input a pair of substrates.
That is, with the preceding assumption that you find an adhesive that likes the anodizing. Have you tried Henckel's site? they have an adhesive picker that lets you input a pair of substrates.
There are plenty of colors available for color anodizing, which is more properly a hot dipped penetrating dye process that adds no additional hardness to the surface, but if you want true hard anodizing, I've only seen it in the 2 colors I described. The anodizing I'm talking about is primarily used for wear resistance, is hard enough to ruin a cobalt drill bit, and outside of stuff made for our uncle, I've only seen it on one other item. There are PLENTY of pretenders, and false claims of hard anodizing out there though. The bulk of these are a penetrating chemical dip/passivation process which imparts a THIN surface hardening, but it pales when compared to true hard anodizing.
You might be thinking of parkerizing which is available in all kinds of colors, including several variations of black. An M16/M4 typically has a parkerized finish.
You might be thinking of parkerizing which is available in all kinds of colors, including several variations of black. An M16/M4 typically has a parkerized finish.
Yeah, I think that's what I know as Type II, which can be done at home with a tank of battery acid and dye.
OK, I think I know that as Invalid Link Removed Type III.
From the Invalid Link Removed: "Type III anodized surfaces can typically only be dyed black or dark green due to the denser pore size. "
Isn't parkerizing for steel? (I'm not an expert, just an enthusiastic amateur, so please correct me if I'm wrong here)
Would it be possible to take advantage of this and deliberately make a large number of very fine finishing passes to get a hardened surface?
I've had parts done in hard coat that came out brown, towards green. But color was not something I specified.
Parkerizing I know of is for steel.
Parkerizing I know of is for steel.
The OP may also consider using a sheet of SS, like a Lefay Remington Steel, rather than aluminum.
Type 3 ano is available in black.
Ano is for aluminum and parker is for steel. They are different processes and arent really interchangable. Anodizing steel will just corrode/disolve it for example.
On another note, you can make your own personal ano setup pretty easily. It takes some thought, time and money but its pretty fun. Not the most useful thing when it comes to bass but whatever. lol
Ive had quite a bit of experience with the process because of paintball. You would be blown away at whats been done on some guns.
Ano is for aluminum and parker is for steel. They are different processes and arent really interchangable. Anodizing steel will just corrode/disolve it for example.
On another note, you can make your own personal ano setup pretty easily. It takes some thought, time and money but its pretty fun. Not the most useful thing when it comes to bass but whatever. lol
Ive had quite a bit of experience with the process because of paintball. You would be blown away at whats been done on some guns.
Yeah, i was just saying in general. I live in an apartment now so sadly the idea is pretty out of the question which sucks. If i were an anodizer id target the music industry a bit. Ive had some pretty sweet anos done to stuff ive owned.
It can be done. This is a Pangborn fretless bass from the early 80's that has an aluminium fingerboard. The fingerboard was recently reattached and has been in place for about a year without problems. I don't recall the type of adhesive that was used though. Pangborn is long gone, but Vigier still makes both guitars and basses using fingerboards made of "delta metal", which is some kind of alloy. Why not shoot Patrice Vigier an e-mail and ask him what he would recommend. I don't think aluminimum is very practical for the reasons others have outlined in depth.
Im not sure if its been asked but since youre using an aluminum fretboard where did you get the aluminum? What grade is it? Will it be rediused? If so how/where are you having that done?
Thanks
Thanks
- Dec 25, 2002
- 9,737
- 310
- 49
- Disclosures
- Owner / Tech: Strange Guitarworks
I'm using 6061 aluminum, and cut it and radiused it myself.
I believe I've devised a mechanical solution: I'm going to thread some pins into the bottom of the fretboard, and glue those into the neck. At this point the entire thing is an experiment, and if it doesn't work I won't be too heartbroken, so I'm in the anything goes stage. I'll let you guys know if I make any progress.
I believe I've devised a mechanical solution: I'm going to thread some pins into the bottom of the fretboard, and glue those into the neck. At this point the entire thing is an experiment, and if it doesn't work I won't be too heartbroken, so I'm in the anything goes stage. I'll let you guys know if I make any progress.
Put some bolts/screws through the fingerboard into the neck, countersunk deep enough and fill the holes with a colored epoxy of your choice. Do this at the proper fret dot marker locations and you're good to go.
That may be kinda akward to work out without it looking funny if he is using a truss rod and reinforcment rods.
- Dec 25, 2002
- 9,737
- 310
- 49
- Disclosures
- Owner / Tech: Strange Guitarworks
I already considered that - but if nothing is going to bond to the aluminum, then my dot markers are going to fall out. Threading into the bottom of the board will allow me to secure it without marring the playing surface.
