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This was mentioned elsewhere and I didn't want to step on an existing thread.

So what needs to be bought? Who from? Filler material, light source, a kit containing both?

Love to get some guidance.

Thanks!

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Peter Havriluk

I got mine used from a dentist so you could ask your dentist. It’s a useful tool to have especially if you’re doing a lot of setups.

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Steve Smith
"Music is what feelings sound like"

I got my stuff from Ebay except for the phosphoric acid. I got way too much of that from Home Depot for way less than an ounce would have cost as a dental supply. You need phosphoric acid, bonder, the filling material, and the curing light. I don’t know why this stuff is available in Ebay. I imagine folks doing their own dentistry on their friends and relatives. So far, the stuff I bought years ago still works, so I don’t know if expiration dates have any meaning.

After the slot is prepared, you brush a bit of phosphoric acid in it to etch it. Then, coat the surface with the bonder and cure it. Fill the entire slot with the filler and cure it. If the gap is too deep, fill it in layers. Where it’s too deep for the light to reach, it won’t cure. If you care, you can get the fill in four different shades so you can pick for a good color match.

And with a Dremel tool and a good mirror, you’ll never have to pay a dentist for a filling again.

Is there a 'system' out there that's more crafty and less dental?

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Peter Havriluk

You can make an inferior repair with CA and bone dust, but this dental system is tough. It files like bone and doesn’t seem to wear any faster. It sure beats making a new nut.

It's way harder than CA and dust and the wound strings have ridges that are like files removing the CA and dust when you tune, not so much with well cured dental fillings.

Our gun came from one of our many dentist clients and two that were students now. The acid etch I'm on the fence about if it's necessary. I prepare the slot with files filing to new, clean surfaces and then making mechanical notches/dovetails of sorts.

I think that we got the idea from Frank, Frank Ford.

The bonder is first for just a little smear and then the fill. Many dental supply houses will sell the bonder and maybe the filler to you direct. I got bonder from a supply house without having to be a dentist.

You can also repair a chipped nut and even match colors as well.

Our stuff for the most part comes from one dentist who brings us his date coded expired stuff for free and we in turn teach him stuff, he's a builder and a hell of a nice guy.

It's a great solution AND..... one more step toward learning to cut nut slots VERY low now that you can go too low and not have to replace the nut.

It's also a P&L center of sorts in that we do charge to fill nut slots since there is some overhead and time here. If I have to fill a slot or two in a repair I add $20 or so to hep cover our costs.

Good going Peter you will be happy to have this capability.

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Ann Arbor Guitars

Got inspired by the talk in the vegan thread and always wanted to add this capability to my shop so went and ordered some stuff. Wow, are there a lot of competing systems of up-cured composite out there. One supplier held stock of about 15 different brands. And then there’s universal composite, flowable composite, syringes vs caps, all the systems have their own proprietary bonders … (are the bonders generic or system specific? )

Eventually I had to stop when I found myself reading dental journal reviews on different systems to determine which had the most highly-regarded color-matching properties

It seems like a lot of these suppliers sell stuff with short expiration dates at a heavy discount… useful if you don’t have a dentist buddy to ask.

Looking forward to experimenting.

A firehose of information. Much obliged. I'm hoping that somewhere out there somebody knows of a package intended for mechanical repairs, not dentistry.

Thanks, everybody.

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Peter Havriluk

This is when I am so grateful to work with Dave he sorts all this out and I only see what results and works.

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Ann Arbor Guitars

Peter my friend I don't think you are going to find a turn-key product/system that is not for dentistry. This stuff is expensive and they, the makers want to keep it that way. If you do find one let me know please? Thanks

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Ann Arbor Guitars

I'm drawing that inference....

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Peter Havriluk

It’s not that expensive. I just looked on Ebay. $43 for the resin kit including a resin assortment of colors, the bonding agent, and the etching acid. $20 for the curing light. That’s cheaper than when I bought mine a few years ago. The stuff lasts a long time. I can’t figure out who buys enough to make a market on Ebay. Dentists ought to be buying supplies that come through vetted channels. Who is doing do-it-yourself dentistry?

The reason you want the dentistry supplies rather than a craft kit is the hardness. The dental fill cures at least as hard as bone. It makes a repair that will last. I suspect the filler consists of glass particles suspended in the resin.

Or just do some work for Dentists and do some trading. That's what we usually do and once in a while I order some bonder from a supply house.

I tend to waste the bonder sadly using a .010" string as a application tool wetting the slot bottom and sides.

I like the flowable stuff Dave likes the stuff with a clay consistency.

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Ann Arbor Guitars

Hey Bob thanks for posting this pic. The bonder is the exactly same brand and stuff that we have been given by our dentist friends and that I have sourced and bought separately too. Your fill is also the same stuff our dentist friends give us as well. your gun is a bit different and newer and nicer IMP. Looks like you got some good stuff there.

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Ann Arbor Guitars

So my gear arrived today and I’m keen to get to messing around with it.

One thing I noticed while browsing the dental supply company’s website was various light-cured glossy resins, glazes and clear coatings. Has anyone ever experimented with these for drop fill or other small finish repairs? I know about UV-cured wood finish products, which have been discussed on here in the past. But I’m interested specifically in these dental products. Frank Ford mentions them briefly on his website but that’s all I’ve ever found on them.

Very cool Josh now when not fixing guitars you can do density too

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Ann Arbor Guitars

Darn straight and this gear should pay for itself in 15 minutes at the rates dentist charge around here

"I am your density" - George McFly.

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"Act your age, not your shoe size" - Prince

I know I am wanting to list my dentist as a dependent on my income tax....

FYI we charge now to fill a nut slot and don't just include it in a bundled set-up price. I've been reworking our pricing for some years now to reflect the value add not the actual costs. So for example raising a few nut slots saves a nut and retains it's functionality. A new nut our way which is only from quality bone hand crafted for the exact guitar is WAY more expensive than what we charge to fill a nut slot now.

So in addition to whatever major job we are doing or just a simple set-up we check the slots at triage and ding the client for an extra $20 per slot up to three of them then it may be shim time for a cheap arse instrument or nut replacement for an expensive instrument.

It does take about ten minutes to get the stuff out, prepare the slot and fill and recut so that's value especially when viewed as saving an original nut. But this is my point, price for the value received not the exact time required. There was a learning curve to learn to do this and our tools wear and tear too with composite dental fillings gumming them up so this is not free for us by any means.

There are lots of Martins with ivory nuts. We won't replace with ivory, go somewhere else we love elephants. But we will fill an ivory nut slot and preserve it's functionality for years to come and again that's real value so consider charging for your new capability and recoup your acquisition costs and more.

You may be buying some nut slot files faster now too it does gum them up some.

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Ann Arbor Guitars

Thanks Hesh, appreciate the details on how you guys do things. I think that’s a great approach to pricing this type of repair.