Strange marks on a Dean Heirloom resonator

[Ben Rennes]

Hi there,

Next week I'm going to try/play a used dobro. The price is lowered because there is oxidation (passage of the arm, hand print) and some cosmetic defects. The action is also very low, which is good for finger play but prohibits the slide.

But above all, he has strange marks on his back. It's as if we had played with a blowtorch or acid right next to it. Its owner tells me that he does not know where it comes from. He does not know if it affects the body or if it is superficial.

So here are my questions:

- do you know what could have caused these traces? Have you ever seen similar ones? Should I be wary of it getting worse?

- Can the action be set on this type of dobro? Is it at worst possible to redo a bridge saddle as one would on an acoustic after a neck-reset for example?

Thank you for your informed opinions


Pictures of the strange marks :


https://ibb.co/S3Yd01W

https://ibb.co/SsBYYBk

[RJVB]

This model? https://fr.audiofanzine.com/guitare-...irloom-copper/

I would take some appropriate cleaning material or ask the owner if he has it and accepts to try to clean those areas in your presence. You should be able to stop whatever corrosion is going on. I wouldn't worry about structural integrity; AFAIK the body those not have a load-bearing role in these instruments (and the spots look small enough that they wouldn't matter even if it had).

Action: it it's (too) low right now the neck is probably fine, or even too straight. IOW, I don't see how a neck reset would be needed unless it was installed at the wrong angle originally. Action can be too low if the cone has sagged or has started to collapse, or if the nut has worn (stock one is plastic apparently). Nut and saddle can be replaced (the latter probably together with the biscuit); the cone can apparently be replaced by (upgraded with) one from National.

For dobro-style slide you can get a nut heightener.

[Ben Rennes]

Yes, it is precisely this one

Thank you for your reply. No worries about body structure then.

For the low action, I did not think to do a neck-reset. But I didn't know if you could change the saddle that rests on the biscuit as easily as on an acoustic guitar. If this can be done without necessarily changing everything (biscuit, cone...), then it's perfect

On the other hand, you scare me by telling me that the cone can collapse But I imagine that it can be seen without dismantling everything, just by observing the place of the saddle?

[RJVB]

Yes, you can see if the cone is compromised. As you can see from the photos the biscuit should be more or less flush with and parallel to the top of the cover plate. You can screw off the hand rest to take a better look.
And don't worry too much: these cones look fragile but they rarely need to be replaced. They're well protected too under that arched cover plate and the hand rest.

Do you have an endoscope or a small mirror on a telescopic stalk? Could be useful to peak through the f-holes. I'd do that with a used resonator, to get an idea of what the cone rests on and in what state it is. Of course you could also ask the seller to show you what further surprises are hidden "under the hood" (almost literally!), easy enough on this kind of guitar but he may not be cool with that

The saddle is probably glued into the biscuit, and I don't think the workshop where these guitars are made will bother using glue that can be dissolved. I know that was the case with my Gretsch, so my luthier just made a new biscuit (not even asking more than his usual price for changing a saddle because it's a single assembly). BTW, biscuit resonator saddles are often sold with the biscuit, from what I've seen.

[Ben Rennes]

Thank you RKVB for all these precious advices
I can't wait to try it next week! The price is under $350, so I can afford a proper set-up by a luthier if needed. At this price, I hope it'll be a good deal.

[Robin, Wales]

It looks like a particularly poor cleaning job before finishing. It could be solder and flux has messed up the application/plating of the finish. Those bodies are relatively expensive to make - nothing goes to waste. So the OEM factory would have produced a finished guitar from it and shipped it to Dean even though it is an obvious second.

The low action doesn't surprise me, nor would a high action - these guitars are very inconsistent out of the factory gate. But, as long as the neck angle is OK, then it should set-up well for any playing style. You are unlikely to find a luthier who has had their hands inside many of these guitars, so you may as well do the set-up yourself. It probably doesn't need a neck reset, but doing one on a metal bodied reso is completely different to doing one on a standard flattop acoustic. In many respects it is easier, but you do need to understand the instrument and not use flattop geometry.

There are some simple tricks of the trade to change a Chinese "banjo" tin box into a rich and resonant guitar. So, if you do buy it, come back here and ask. I've torn apart and rebuilt somewhere around 800 reso guitars, and still have the mental scars!!!

[Ben Rennes]

Thank you Robin. About 800 reso guitars? Well, I'm very impressed!
As the worst meets the best in this price range, I will move to try it next week, even if it is not that expensive. Then, of course, I'll ask for help if the trial convinces me to buy it!

[Robin, Wales]

That's a good idea Ben. It is definitely worth having a look at the guitar. It is probably better built that a lot of the old 1930s originals!

I used to own Busker Guitars, which why I have had my fill of setting up reso guitars!!!

[Ben Rennes]

Hi,

Well, the reso is sold and the seller canceled my trial next week
I'm going to watch the ads for budget resos (Dean, Republic...) on the web until I find something that suits me.

Thank you for your help and see you soon for questions about another model