What to use for filling small cracks in guitar body

[Artwerk Orange]

I read this when you first posted it. Then wanted to find it again, thinking the comment had been about cracks in MY project. It seemed appropriate for me, too, since my slab was not sitting long enough to dry by conventional wisdom. This is the post I was looking for.

I'm off to order the Z-poxy. I found the Stew-Mac video very helpful.

Let me know if the Z-Poxy works. I have tried BlueFixx and it did the job for a very small chip. I will check back. Thanks,
Craig

 

[duck69]

Mohawk makes an epoxy 2part putty stick that’s awesome. Comes in a variety of colors. Dries hard as a rock in 10-15 minutes. Won’t shrink or crack. You have to be quick. Working time is about 7 minutes. Make sure you over fill the crack-hole just a little as this is a bear to sand by hand, not so bad with an orbital sander. Just don’t sand in one spot too long or you will create a divot. Make sure to move sander over entire surface. I have been using this stuff for 25 years it has saved my butt more than once. Over route an inlay use this stuff instead of dust and superglue if you get a color match you like. I do furniture repair as well as building guitars I have made repairs doing commercial touch up to doors using this stuff that would blow your mind. Check it out you won’t be disappointed.

 

[duck69]

This is their pine color. You slice off a little and mix it up with your fingers until it’s one color. Don’t slice off too much or you’ll find yourself wasting it as it hardens quickly. Then apply it with a putty knife. A trick to getting it real smooth is to lick your putty knife when smoothing out your last pass. Get some spit on that thing. You can mix colors to create a custom color. These only come in wood tone colors unless they’ve added more colors lately. I can’t recommend this product enough.

 

[duck69]

Mohawk epoxy putty stick m-743-1500

 

[Bass Butcher]

Saw dust from same wood, preferably, mixed with glue. Sand over.

You got it, mixed with either carpenter's or white glue. It is how professional hardwood item manufacturers have done it for as long as white and carpenter's glue has existed.

 

[Bass Butcher]

I was a woodworker and assistant to the master woodworker in the top church and courthouse interior/furniture factory in North America, established in the late 1800's. As a previous commenter correctly stated, sanding powder obtained from sanding the item or the same lumber, mixed into a wood paste with just enough carpenter's or white glue to make it malleable. You don't need a 'special' glue and there is no benefit to using them, or a plastic or epoxy for this purpose. Pack it tight into the crack with a small blade (1" is good), flexible putty knife, making multiple passes (across helps fill it, diagonal passes help pack it). On items that are already final sanded, for larger cracks/pores, I will pack dry sawdust at the end to get maximum color consistency. You can overfill it a bit and sand it back to the surface (like mudding drywall joints), whether it is pre sanded or just needs a final sanding to blend it in. This makes as close to an invisible filler as you are going to get and takes a few hours instead of days or weeks to cure. Done properly it is invisible after sanding, so definitely the best option for stained items. As the master woodworker's assistant I did this to get rid of small defects or fill larger grain pores on highly visible items pretty much daily. Oak pew/court bench ends, pulpits, etc.

I would never consider using a premade wood filler or a plastic/epoxy compound for filling any wood item that wasn't going to be painted. Even for a painted body/item I wouldn't use a hardware store premade wood filler. About the only thing I will use it for is filling finishing nail head indents on wood trim. It shrinks, cracks and will often return to a powdered state after a few years when used as a surface filler or for larger cavities. I've brushed a lot of it out of neck pockets on bolt on electrics over the years. Plastics and epoxies are harder than most woods once cured, which makes sanding them flush a challenge, even if you wrap the sandpaper around a milled maple block to get a perfectly flat backing for the paper.

 

[Esquier]

sawdust and superglue is another

That's what I was going to say!

 

[wolfman2020]

Hi all,

I recently made my first "from scratch" body using alder from a local hardwood store. After milling to thickness there's a few small cracks on the surface of the wood. I was looking at a burst strat I have, and it looks like it may have had a similar issue, and the cracks were filled with "something". Wondering if any have recommendations on what to use to fill. In other (non-guitar) projects I've done, I haven't had great luck with standard wood fill, as it tends to swell a bit over time.

Thanks in advance.

Gary

Hi Gary I refinished an old 69’ Gibson Les Paul deluxe Goldtop with a crack by the volume and tone controls and I used wood filler. When I finished painting it, it came out perfect and after a couple of weeks I started to seeing a small dip back in the body line where I had filled it. I talked to stewmac and I was told I should have used some wood in the crack, he said they always want to open back up. So you might try gluing a small piece of wood into the crack. They said that wood prevent it from coming back

 

[SkinnyAss]

Hi all,

I recently made my first "from scratch" body using alder from a local hardwood store. After milling to thickness there's a few small cracks on the surface of the wood. I was looking at a burst strat I have, and it looks like it may have had a similar issue, and the cracks were filled with "something". Wondering if any have recommendations on what to use to fill. In other (non-guitar) projects I've done, I haven't had great luck with standard wood fill, as it tends to swell a bit over time.

Thanks in advance.

Gary

Some 50 years ago, my woodshop teacher taught us to make a belt sander glue paste with whatever wood we were trying to patch.

 

[myfenderissues]

Hi all,

I recently made my first "from scratch" body using alder from a local hardwood store. After milling to thickness there's a few small cracks on the surface of the wood. I was looking at a burst strat I have, and it looks like it may have had a similar issue, and the cracks were filled with "something". Wondering if any have recommendations on what to use to fill. In other (non-guitar) projects I've done, I haven't had great luck with standard wood fill, as it tends to swell a bit over time.

Thanks in advance.

Gary

it depends on how large the cracks are, but wood grain sealer, aka sanding sealer, is used over bare wood even on alder, which is a tight grained wood. fender uses a product that's very thick, basically an epoxy, under their finishes for a grain and sanding sealer. even nitro fenders, pre cbs fender, used this very thick, epoxy resin which, btw, counters the argument that a vintage, thin nitro finish of the pre cbs fender guitars allowed the wood to resonate more freely than the later, poly finishes used after cbs bought fender. for larger cracks you can try mixing sawdust with wood glue, but in my opinion it leaves a result that may be filled flat but it's not suited for a clear or semi clear finish. for a medium or larger crack i'd graft a piece of matching wood in and sand it flat

 

[enorbet2]

For a solid body with small cracks it really doesn't matter much beyond getting a good solid bond. A filled small crack won't alter resonance enough to make a sonic difference. I tend to use sawdust, thin super glue and accelerator for solid bodies.

For acoustic guitars I try to get fine sawdust of the same wood but instead of super glue I use Urea Resin since it's properties ar very much like natural cellulose.