Filling cracks on an unpainted body

[GWKing]

Hi all,

Apologies - I have a query that's not about a Strat - it's about a Tele. I have very little experience about woodworking, gluing or any of the prep processes, but at 35 it's about time I learned something! I'm hoping you lovely peeps can slap me about with some information as to whether the below is salvageable, or what you would do with it.

I've bought a Swamp ash body for cheap (second hand) that needs a lot of work. It also has quite a lot of tool marks, and more alarmingly, some fairly large cracks. I'm perfectly aware the tool marks can be sanded out (some areas aren't perfectly flat fyi) or grain filled, but what can I use to fill the cracks at this stage of a build that will not break out again? Is there such a solution?

You can see one crack between the lower horn and the neck pickup rout, and then a large crack in the neck pocket... It doesn't fill me with hope, I'm assuming these are out of the shop as they are circled in pencil and numbered, but either way I paid £40 for it so happy for it to be a learning project. It's just that if it's salvageable, I would dedicate the time to doing it to the best of my ability.

Thanks for taking the time to read this far. Any input would be gratefully received.

 

[tmcq]

I would fill with repeated applications of cyanoacrylate (super glue). I had one large crack on a similar Tele body, and finished with a semi-transparent Butterscotch Blonde Nitro. The crack is visible through the finish, but is full flat and rock solid, and kind of looks like a grain feature. You could also sand up some fine dust with 400 grit to mix in with the CYA glue.

Can't find a good pic after the finish, but here is the crack before and after sanding the CYA:

 

[GWKing]

I wondered how long it would take for someone to say superglue!

In all seriousness - superglue is okay to use (cryanoacrylate)? I ask that because wood obvious moves, "breathes", flexes, etc., but superglue does not. Doesn't it just cause further damage over time?

Thank you!

 

[Believer7713]

Those cracks are from someone getting in a hurry and not letting the wood completely season and dry. How are you planning on finishing it?

I have one that I plan to epoxy fill but it is going to be painted an opaque color.

 

[GWKing]

Those cracks are from someone getting in a hurry and not letting the wood completely season and dry. How are you planning on finishing it?

I have one that I plan to epoxy fill but it is going to be painted an opaque color.

Oh really? That's interesting to know - how do you know that? Both cracks go in the same direction against the grain so assumed it was some sort of issue with the wood.

I'm thinking a solid finish. I love the Miami blue but that's a colour I can't find the paint code from Fender for so thinking of buying some Porsche Miami Blue paint as it's similar (not the same), and then clear nitro lacquer - all spray cans under this tutorial.

So far I'm aware of;
1. CA or Superglue
2. Epoxy
3. Wood glue with wood shavings

I'm personally siding on number 3 as the body needs a lot of sanding still anyway, but also not adverse to 1 or 2. I really just want what's best for the integrity of the body.

 

[Scott Baxendale]

Hi all,

Apologies - I have a query that's not about a Strat - it's about a Tele. I have very little experience about woodworking, gluing or any of the prep processes, but at 35 it's about time I learned something! I'm hoping you lovely peeps can slap me about with some information as to whether the below is salvageable, or what you would do with it.

I've bought a Swamp ash body for cheap (second hand) that needs a lot of work. It also has quite a lot of tool marks, and more alarmingly, some fairly large cracks. I'm perfectly aware the tool marks can be sanded out (some areas aren't perfectly flat fyi) or grain filled, but what can I use to fill the cracks at this stage of a build that will not break out again? Is there such a solution?

You can see one crack between the lower horn and the neck pickup rout, and then a large crack in the neck pocket... It doesn't fill me with hope, I'm assuming these are out of the shop as they are circled in pencil and numbered, but either way I paid £40 for it so happy for it to be a learning project. It's just that if it's salvageable, I would dedicate the time to doing it to the best of my ability.

Thanks for taking the time to read this far. Any input would be gratefully received.

These are humidity cracks caused by the body drying out after it was machined. I would fix this by wicking superglue into the crevasses then filling them with baking soda and then wicking more superglue on top of that until the cracks are fully filled then I would block sand the surfaces flat. Next I would use water based Wonderfil wood filler to skin the entire guitar. Next I would block sand the entire guitar with 320 grit. Then I would either stain the wood and then seal it with vinyl sealer or just vinyl sealer with no stain, if I’m doing a solid color. Now it’s ready to paint with lacquer.

 

[GWKing]

These are humidity cracks caused by the body drying out after it was machined. I would fix this by wicking superglue into the crevasses then filling them with baking soda and then wicking more superglue on top of that until the cracks are fully filled then I would block sand the surfaces flat. Next I would use water based Wonderfil wood filler to skin the entire guitar. Next I would block sand the entire guitar with 320 grit. Then I would either stain the wood and then seal it with vinyl sealer or just vinyl sealer with no stain, if I’m doing a solid color. Now it’s ready to paint with lacquer.

Thanks Scott! Much appreciated! I'm glad I didn't jump into this straight away! I'll definitely do that tomorrow then, I just got some liquid CA super glue today - O3a brand from my local wood yard. The body has been sanded and I saved a tub of the ash dust just in case I needed it, but it's going to be painted so it doesn't need to be decorative.

I was also looking at buying Rustin's grain filler. I live in the UK and am pretty far away from a lot of places. If I'm looking at the right stuff, Wonderfill is made by Deluxe Materials? Is there any advantage to wood filler over grain filler(?) or is it same same with a different name? It sounds like wood filler is stronger through a Goog search. I'd have to order it for delivery, but I'm in no hurry. Grain filler is available to me, but if Wonderfill is genuinely a better option then I'll hang fire for that.

 

[Scott Baxendale]

Thanks Scott! Much appreciated! I'm glad I didn't jump into this straight away! I'll definitely do that tomorrow then, I just got some liquid CA super glue today - O3a brand from my local wood yard. The body has been sanded and I saved a tub of the ash dust just in case I needed it, but it's going to be painted so it doesn't need to be decorative.

I was also looking at buying Rustin's grain filler. I live in the UK and am pretty far away from a lot of places. If I'm looking at the right stuff, Wonderfill is made by Deluxe Materials? Is there any advantage to wood filler over grain filler(?) or is it same same with a different name? It sounds like wood filler is stronger through a Goog search. I'd have to order it for delivery, but I'm in no hurry. Grain filler is available to me, but if Wonderfill is genuinely a better option then I'll hang fire for that.

You can order Wonderfil through Rockler. It can be used as a gap filler or a grain filler such as in this application. Oil based grain fillers are a lot harder to work with and take a lot longer to dry. With a heat gun wonderfil dries in seconds or minutes, not hours like oil based filler. Wonderfil can be thinned with water or used as a paste with the consistency of creamy peanut butter. I use an auto body filler spatula to apply it, then use a wet Terry cloth rag to clean up the excess after it dries.

 

[GWKing]

You can order Wonderfil through Rockler. It can be used as a gap filler or a grain filler such as in this application. Oil based grain fillers are a lot harder to work with and take a lot longer to dry. With a heat gun wonderfil dries in seconds or minutes, not hours like oil based filler. Wonderfil can be thinned with water or used as a paste with the consistency of creamy peanut butter. I use an auto body filler spatula to apply it, then use a wet Terry cloth rag to clean up the excess after it dries.

I see - we don't have Rockler here in the UK and they won't ship Wunderfil to the UK anyway. I get to the checkout and they're flat out refusing.
I've bought some Rustin's Grain Filler as I've heard good things about it in the UK guitar builder's scene. I'm in no hurry regarding drying times. I do worry about the integrity of the body but if we're happy that CA glue is good enough, I'm well on my way. Thanks folks!

 

[Believer7713]

Oh really? That's interesting to know - how do you know that? Both cracks go in the same direction against the grain so assumed it was some sort of issue with the wood.

I'm thinking a solid finish. I love the Miami blue but that's a colour I can't find the paint code from Fender for so thinking of buying some Porsche Miami Blue paint as it's similar (not the same), and then clear nitro lacquer - all spray cans under this tutorial.

So far I'm aware of;
1. CA or Superglue
2. Epoxy
3. Wood glue with wood shavings

I'm personally siding on number 3 as the body needs a lot of sanding still anyway, but also not adverse to 1 or 2. I really just want what's best for the integrity of the body.

Sorry, I didn't get back earlier. I was still in and out a lot from the surgery last week. About and I are in agreement on what caused the cracks and he definitely had you going in the right direction. Good luck with the work. Look forward to seeing it when it's done.

 

[Miotch]

I'd fill them with epoxy or a two-part wood filler (which is basically a wood-colored polyester, based on the smell), which sands nicely. That body is perfectly useable if you are going to paint it opaque.

 

[Scott Baxendale]

I see - we don't have Rockler here in the UK and they won't ship Wunderfil to the UK anyway. I get to the checkout and they're flat out refusing.
I've bought some Rustin's Grain Filler as I've heard good things about it in the UK guitar builder's scene. I'm in no hurry regarding drying times. I do worry about the integrity of the body but if we're happy that CA glue is good enough, I'm well on my way. Thanks folks!

The Rustin’s is a mineral spirit based product, which is the old traditional grain filler that we used 30 years ago. It’s hard to work with, hard to clean up and takes quite a while to dry. You need to apply it in circular motion with burlap, then when it dries to have to scrub off all the excess with more burlap rubbing against the grain. Just rubbing off the excess takes a lot of elbow grease and a hour of hard scrubbing to clean off the excess. Then is sometimes shrinks down into the grain in effect not fully filling the grain.


Wonderfil is a latex water based product that you can thin or reactivate with water. You can apply with with a rag or a spatula. It dries in a few minutes and cleans up in seconds with a damp rag. There must be someone in the UK selling this? Look up water based grain filler to see what else is available.

The mineral spirit based wood filler has been obsolete for a long time now.

 

[GWKing]

Hey @Believer7713 - thanks for your input. No worries, I hope you have a speedy and full recovery!

@Scott Baxendale - Okay, I shall cancel the Amazon order. It doesn't arrive until Thursday so I'm sure it'll just be redirected in transit.

There must be someone in the UK selling this?

Honestly? There's a lot of American products mentioned on these forums that we don't have access to unless we pay for StewMac to export (import) to us over the pond. I even had to google what a Terry cloth was - in the UK that's just a towel, or towelling fabric as far as I'm aware. Woodworking is not a skill a lot of little Englanders pick up as our modern house development doesn't really give us the space to do it and wood is expensive, therefore the market for supplementary products aren't in huge demand. Since the B-word, a lot of countries are pulling products and the ability for us to import due to paperwork on unnecessarily small items.

Even the tutorial I was following (here) has a grain filler from Germany. I've validated how much that costs through a German friend and it's like £8 in their home country but it's £43 for us to get in the UK so I'm having to deviate. The store he refers to as a good source for the lacquer (Guitar Tech Manchester) has Rustin's Grain Filler as the only 'sundry' available: https://manchesterguitartech.co.uk/product-category/sundries/

When I google Wonderfil, I get this stuff: https://deluxematerials.co.uk/products/wonderfill
Following your description, this is the closest I can find from a reputable brand in my local wood yard: https://www.yandles.co.uk/liberon-wood-filler/p13881
I'd appreciate your input on this, or can provide more links if you've got time to spare, but can't find Wonderfil in the UK I'm afraid.

 

[Slacker G]

Who is to say that it won't warp or crack again in another area? You can purchase new guitar bodies for as little as $35-50 on the Internet that won't crack. As for me, I wouldn't trust that hunk of wood, but that's just me.

 

[Scott Baxendale]

Hey @Believer7713 - thanks for your input. No worries, I hope you have a speedy and full recovery!

@Scott Baxendale - Okay, I shall cancel the Amazon order. It doesn't arrive until Thursday so I'm sure it'll just be redirected in transit.

Honestly? There's a lot of American products mentioned on these forums that we don't have access to unless we pay for StewMac to export (import) to us over the pond. I even had to google what a Terry cloth was - in the UK that's just a towel, or towelling fabric as far as I'm aware. Woodworking is not a skill a lot of little Englanders pick up as our modern house development doesn't really give us the space to do it and wood is expensive, therefore the market for supplementary products aren't in huge demand. Since the B-word, a lot of countries are pulling products and the ability for us to import due to paperwork on unnecessarily small items.

Even the tutorial I was following (here) has a grain filler from Germany. I've validated how much that costs through a German friend and it's like £8 in their home country but it's £43 for us to get in the UK so I'm having to deviate. The store he refers to as a good source for the lacquer (Guitar Tech Manchester) has Rustin's Grain Filler as the only 'sundry' available: https://manchesterguitartech.co.uk/product-category/sundries/

When I google Wonderfil, I get this stuff: https://deluxematerials.co.uk/products/wonderfill
Following your description, this is the closest I can find from a reputable brand in my local wood yard: https://www.yandles.co.uk/liberon-wood-filler/p13881
I'd appreciate your input on this, or can provide more links if you've got time to spare, but can't find Wonderfil in the UK I'm afraid.

Try the deluxe materials product.

 

[GWKing]

Thanks @Scott Baxendale - will do and I'll post the final result.

@Slacker G - again UK based so not really the same market as you folks in the US have. I can find Tele bodies in varying conditions from £40 ($50) all the way up to £500, but Tele deluxe bodies... not so much. Donations always welcome though!

 

[GWKing]

I'd fill them with epoxy or a two-part wood filler (which is basically a wood-colored polyester, based on the smell), which sands nicely. That body is perfectly useable if you are going to paint it opaque.

Thanks @Miotch - Minwax is available in the UK but it's running at £37 which is $46, plus £10 ($12) shipping. Is this correct? Seems steep to me.

 

[Miotch]

Probably the same stuff. It costs about $19 U.S. here where I bought some. Smells like your laying fiberglass with polyester resin when mixed up.

 

[GWKing]

Update for those who are interested.

I sanded down the body. There were some pretty hideous machining marks in the belly cut (picture 1) which gave a fight. I also filled in the cracks (as above and picture 2 on the back) with Baking soda and ca glue before sanding back (pictures 3 and 4 and 5). I got a bit too liberal with the sander and can see I accidentally took off a little on the lower horn (picture 3).

Wonderfill (Deluxe Materials - UK version) arrived and I spent a morning filling the guitar cracks - that stuff was non-toxic and can (should) be applied by hand, but it was an absolute b████rd to apply smoothly with tools because it just stuck to them. It's basically like marshmallow fluff with quite a lot of a resistance. It didn't go down well and so I skimmed a second coat over it to get an even coverage and level sand back - I didn't take any pictures of this because of how embarrassed I would be; it looked hideous! I got the majority of it off but some of it started to pool like a hard crust that may have bonded to something on the surface. I thought the volume of dust that was on the surface of the body would be a real problem so I hastily thought I'd wipe it down with white (mineral) spirit... Initially this was a BAD idea as it was literally eating the stuff away, however in hindsight it has removed the majority of the crusting on the surface and upon further inspection, I am confident I have now have a mostly level body with the pores now filled with filler.

There is still some work to be done, but you can see the white is filling in the cracks nicely. Picture 5 3 shows some horrible dings and dents whilst picture 6 shows the after effect of using Wonderfill. Picture 7 shows those machining marks (in 1) are now mostly removed, and also the Wonderfill has filled some of those channels. Unfortunately the sharp edge for the cut has become less defined after sanding even though I was careful to do this bit by hand.

Next steps? I need to address the lower horn somehow - maybe try this Wonderfill again and see if I can create a smoothed out lower horn but that might just crumble the first time it's dinged. Other than that, not sure... I'm also looking at buying sanding sealer and primer from a guy called Manchester Guitar Tech (UK Manchester) - his cans are pricey (to me), and his only delivery option is next day (and therefore pricey too) so it then makes sense to get the top coat as well rather than making 2 separate orders and paying double delivery fees, but that's a lot of moneys for me to order this month considering what I've already laid down, so probably waiting on it for now.

As always any input greatly appreciated and loving the learning!

Edit: picture order rearranged itself so renumbered in the text above.