Self-build: which should I file down?

[AuntieBeeb]

Hello all. I'm a bit new to this but it seemed like the best place to go for some technical advice.

So: I recently purchased a P-bass-like body from eBay. It was only after receiving it and making a few measurements that I realised the neck pocket was too small. Most Fender-style necks appear to be about 63mm wide at the heel, whereas this is only about 53mm.

The obvious answer, I realise, would be to file a few mm off either side of the neck pocket so I could buy a neck and bolt it in. However, whilst I could get hold of a maple-rosewood neck fairly easily and cheaply, this body is a gorgeous one-piece made from mahogany. Therefore I'm now wondering whether I'd do better to file the extra off the end of the neck (knowing that the rosewood fretboard would still sit proud of the pocket and therefore not need filing).

What would you do?

Alt Q: Oils. I don't really have the facilities to do a decent job of varnishing it, so I was thinking of treating the wood with a combination of linseed oil and French polish. This worked wonders on a cheaper bass (ash body, I think), but would you suggest anything better for a mahogany body?

[202dy]

The body is not to Fender spec. The neck will be.

So the question is whether to fix something that is broken or to break something that is not. If the neck becomes the workpiece the result will be two, one-of-a-kind components mated for life.

From a more practical standpoint, modifying the neck pocket is relatively straight forward. The best way to accomplish the task is to use a router and template. However, it can be done with a sharp chisel by hand. That is, if the person doing the work is a tool user and has good hand skills. If done correctly, that is the end of the project. It is time to bolt up, string up, set up, and play.

Modifying the neck for a precision fit is much more difficult. There are no commercially available templates. It would have to be created by the user. The alternative is to use a saw, stops, and chisels to waste the wood. Sanding and finishing come next. In any scenario, the taper (or lack thereof) on the body routing must be centered and precision matched to the bottom of the neck. All of this whilst insuring the fingerboard is left unharmed.

Some will suggest attempting to return the body. You have indicated that you like this piece of wood. So that does not appear to be an option.

[Ric5]

Simply remove a little bit of wood from the neck pocket, and if you don't have a professional wood shop a dremmel tool and a little bit of careful effort will give you what you need. Oil finish can be applied by a semi-skilled amateur with good results. I use tung oil with a small amount of mineral spirits added.

[AuntieBeeb]

Originally Posted by 202dy

From a more practical standpoint, modifying the neck pocket is relatively straight forward. The best way to accomplish the task is to use a router and template...There are no commercially available templates. It would have to be created by the user. The alternative is to use a saw, stops, and chisels to waste the wood.

The only tricky bit is...I don't have a template! If I were to chop anything off either part, it would be a case of trying to make some measurements and tentatively taking a chisel to it. It certainly looks like this would be easier to do on the body. (Plus if I were to make a complete hash of it then the neck would still fit any standard-template P-bass body!)

Thanks for your advice!

[Hugh Jass]

Originally Posted by AuntieBeeb

The only tricky bit is...I don't have a template!

Trace the neck profile onto cardboard or some other cardstock type material, cut out the inside and tape it to the body. There's your template.

[Nev375]

Cardboard isn't hard enough to use as a router template. Re-routing a neck pocket is very difficult to do right. It's not a job for beginners.

Also a 10mm difference is huge. Even having a professional do it, i'm not sure I'd be happy with the end result. (5mm overhang on either side)
If it were me, i'd sell the body and get one made to fender specs ($$$ i know) or wait around for a more compatible neck. (could be a while)

[202dy]

Originally Posted by AuntieBeeb

The only tricky bit is...I don't have a template! If I were to chop anything off either part, it would be a case of trying to make some measurements and tentatively taking a chisel to it. It certainly looks like this would be easier to do on the body. (Plus if I were to make a complete hash of it then the neck would still fit any standard-template P-bass body!)

Thanks for your advice!

Templates are readily available from Stewart-MacDonald and other suppliers. Assuming this is project is not a lark, there is time to collect the proper parts and tooling.

Card stock will not be thick enough nor sturdy enough to support a top bearing router bit.

This is not a job for a Dremel tool. Minimum size tool for this job is a laminate trimmer. A router with a rating of 1 1/2 horsepower would be better.

[AuntieBeeb]

Hmm...the more replies I read, the more I think I might be better off selling the body. To be honest, I was hoping to make this a relatively simple project of just harvesting some suitable parts to bolt together but that neck joint threw me somewhat. I'd have been apprehensive enough about taking a chisel to either part, but all this talk of laminate trimmers and routers is putting me right off!

[202dy]

If you are strictly a parts assembler this project will stretch your skills. The hard part is learning the skill. Practice takes care of that. Just repeat the mantra: Practice On Scrap!

If it sounds too scary, a pro can make the cuts on the body and you can assemble the parts as usual.

[Pilgrim]

Originally Posted by AuntieBeeb

Alt Q: Oils. I don't really have the facilities to do a decent job of varnishing it, so I was thinking of treating the wood with a combination of linseed oil and French polish. This worked wonders on a cheaper bass (ash body, I think), but would you suggest anything better for a mahogany body?

You probably know this, but basses are not varnished, they're painted. All you need to do the job is a few different grits of sandpaper, some wood sealer, a couple of rattle-cans of undercoat and paint, and some finishing polish. No facilities needed other than a place to spray the finish - which you can do on a sidewalk if you're careful.

Alternatively, you can certainly go the oil route, and there's plenty of info on TB about various techniques. You may want to stain the body to bring out the grain. Mahogany is pretty open-grained, so unless you seal the wood it will accumulate dirt over time. Personally I like Birchwood Casey's Tru-Oil for a hard seal finish...there are many discussions of it if you search.

[Hugh Jass]

Originally Posted by Nev375

Cardboard isn't hard enough to use as a router template.

Woops, should have specified that I was talking about a template for using hand tools.

[walterw]

Originally Posted by 202dy

The body is not to Fender spec. The neck will be.

So the question is whether to fix something that is broken or to break something that is not.

excellent point.

also, if the neck pocket is indeed completely wrong for standard fender necks, what makes you assume the rest of the body specs are right?

it may be a pretty piece of wood, but it could be a total nightmare trying to get a working fender bass body out of it.

[96tbird]

+1 walterw, however you can find a PROFESSIONAL cabinet maker to rout the pocket to specs. It should be no problem for one to make it perfect. Give him the neck so he can make a tight fit and implore him how critical it is that it remain parallel to the existing side of the pocket! However you will likely, like NEV375 says, have the neck overhanging the heel 5mm on the treble side, the bass side shouldn't be too bad as there is alot of wood there to work with. Your call.

[bassman10096]

It's hard to tell how much wood really has to be removed, but if it's a modest amount the Dremel sanding drum approach is easiest and safe enough (go s l o w, check your work constantly). I would not take a chisel to that neck pocket unless I were a real woodworker (too many irreparable mistakes at hand waiting to be made). If a lot of wood has to be removed then I'd find a luthier (who actually builds guitars) or a great woodworker and make sure they have the standard Fender pocket template. Here are the standard Fender dimensions: http://www.warmoth.com/Bass/Options/...PocketPop.aspx. Pay close attention to the depth of the pocket -- too deep means lots of shimming (have an experienced repair shop do this) and often bad results. If the pocket has to be deepened, well, you're in luck: You'll have to find a routing template and have someone experienced in routing do the honors (this might be better in the long run because all the dimensions can be fixed at once). Here's a reasonably priced routing template from a great supply house.
As to the finish - you can definitely do a Tru-oil job, but as was pointed out, the open grain of the Mahogany will always catch dirt. I've done a large number of bodies with plain old polyurethane in a spray can. It's easier than you think. Just get some ultra fine wet/dry sandpaper and smooth the finish off before each new coat (it will be dull but smooth when ready for the next coat). Build up 8 to 10 coats of urethane and you'll have a great protective finish and it can be finished to high gloss (I couldn't believe how well my first effort with urethane worked). Two more things: You'll need to fill the mahogany's grain before finishing - use an oil based filler. Then - you'll need more info on prepping, spraying and rubbing out a finish. Reranch specializes in nitrocellulose lacquer finishes and sells exclusively nitro-compatible materials, but the techniques explained on their website are exactly the same as you'd use for a polyurethane finish (just don't try to mix urethane and nitro!). I doubt they ship nitro overseas (restrictions on air shipping) and frankly, nitro isn't the easiest first effort. Here's their website page with instructions on prep and finish: http://reranch.com/101.htm.