How To Fill A Pickup Cavity

[silvertonessuckbutigotone]

This is my tutorial on filling a pickup cavity using Bondo. There are two ways to do this. The first way is to make a peice of wood to fit inside the cavity and glue it in with titebond then fill it with bondo. This method takes longer and is only necessary if the area of filling will have stress on it in the future (i.e. bridge screw, etc.). The other is to completely fill the cavity with bondo. I will describe both.

BONDO WITH PEICE OF WOOD

1. Make sure the area to be filled is completely rid of any paint or dust.

2. Using a bandsaw cut the peice to the approximate size of the cavity to be filled. To do this I took a peice of paper and set it on top of the cavity and lightly scribbled on it and you can see the outside lines of the cavity

then cut out the peice of wood.

3. Glue it in using titebond, not titebond II, just regular old titebond.

4. Level sand to make sure the top of the peice of wood is at or below the top of the guitar.

5. Blow out any dust from inside the sanded cavity.

6. Mix the bondo on anything thats non absorbant and somewhat smooth, a plastic bowl worked fine for me. Follow the directions on the can for proportions.

7. Using a scraper put some bondo in the holes left from the imperfections of the wood peice inside of the former pickup cavity.

8. Step 7 most likely wont be your last pass with the bondo as the bondo will sink farther into the holes, but it is a lot easier to fill the holes after the first pass is dried and sanded. So once the first is dried, sand it level.

9. Go over the holes again and again sanding in between passes with any grit below 150. Do this until you are satisfied with the final product. Sand to 220 and you are ready to go.

Completely filling with Bondo.

1. Blow out any dust from inside the cavity. Make sure it is somewhat clean, no huge mountains of dirt or anything.

2. Mix the bondo on anything thats non absorbant and somewhat smooth, a plastic bowl worked fine for me. Follow the directions on the can for proportions.

3. Using anything to hold the bondo put some bondo into the former pickup cavity.

4. Step 3 most likley wont be your last pass with the bondo as the bondo will sink farther into the cavity, but it is a lot easier to fill the holes after the first pass is dried and sanded. So once the first is dried, sand it level.

5. Go over the cavity again and again with the bondo sanding in between passes with any grit below 150. Do this until you are satisfied with the final product. Sand to 220 and you are ready to go.

I will also explain how to fill potholes (hehe potholes) using bondo.

1. Going from under the guitar in the control cavity tape the bottom of the hole to contain the bondo.

2. Fill it with bondo.

3. Let'er dry and sand, and yer done.

I'll probably get some pictures up tommorrow when I'm not lazy. Any questions or comments will be welcome.

Edited October 31, 2004 by silvertonessuckbutigotone

[silvertonessuckbutigotone]

I put it in html format w/ pics, sorry for crappy pics. I'll try to get better ones when I can, I was in a hurry.

Tutorial

Edited November 1, 2004 by silvertonessuckbutigotone

[guitarman]

Silvertonessuckbutigotone

I just wanted to thank you for being so respectful with your posts about KWS.

I thought you were eloquent and very polite. While other people took it personally and tried to put me down (like some high school clique) you disagreed politely and made some damn fine points.

I think I might have been too hard on the lad.

I STILL think that guitarists are a little too eager to follow fashion.....but we can agree to disagree.

We are both secure enough!!

You are a good man.

Thanks,

Guitarman

ADMIN EDIT: This belongs in email or PM. Next time, please do so.

This post will be deleted soon.

[HarrisonD]

I plan to start tinkering with an old beater that I bought new for $100 a decade ago.  It's got two humbuckers and I want to convert it to a strat-style 3 single-coil pickup setup.  Would it work to fill the pickup cavities via this woodblock+bondo solution and then route out fresh cavities for the single-coils, knowing that the new cavities would necessarily overlap  some with the old filled ones?  I'd Imagine I might have to expect some cracking in the bondo when routing but I'm hoping it would be easily patched and wouldn't be too structurally compromised. Is this a dumb idea that I should scrap or pretty doable?

[Bizman62]

Hi @HarrisonD and welcome to the forums!

The woodblock+bondo method is fully valid for your purposes. I haven't used Bondo, instead I've fixed smaller holes with the 2k resin putty that comes as dual layer sticks you roll into a homogenous mass before applying. The most important thing is that the stuff used should not shrink and rather not flex too much. Structurally even cracks don't matter too much as there's been a big hole to start with.

If the bottoms of the humbucker cavities are flat even snugly fit glued-in blocks should do, wood dust and glue being used as filler. But as the cavities often have deeper ends for the screws some Bondo type non-shrinking putty is much easier than fitting tiny blocks to cover them and a larger one for the rest of the cavity.

[MiKro]

Why not just do a swimming pool route?

MK

[j.butt31]

I was thinking of turning an off brand strat into my own Frankenstein and was thinking of filling in the 3 single coil holes to put in a humbucker in the neck and bridge position. Would the wood+bondo method work for this?

[Bizman62]

Hi and welcome!

23 minutes ago, j.butt31 said:

Would the wood+bondo method work for this?

I can't see a reason why it wouldn't. If it's a standard three cavity strat, all you have to do is to fill the middle cavity and then rout or carve the two other ones to fit the humbuckers. If you're going to use a pickguard you can choose an even simpler way: Simply carve the bridge and neck cavities larger and leave the middle one as is.

If you're going to fill the cavity, don't forget to leave a channel for the neck pickup wire!