Question about glues

[chrysophylax]

First of all hello to everyone on this forum. I'm new here, but not so new to building instruments (at least not complete newbie). I have a couple of questions about gluing plastic binding to wood.

Here's my project - I'm building traditional Croatian instrument called "tambura". It's fairly similar to acoustic guitar, with some differences. Here is the image of this instrument, i know it's not related to question but I would like to introduce it to you (this one was made by Croatian's best luthier)



Anyway, I'm about to put binding on my tambura soon, it will be black plastic strip which I've cut from some old garbage can (I can't order bindings from Stewmac since i don't have pay pal so I have to work with what I have lol).

Here are my questions:

1. Which is the best to use (since I can't get StewMac cement): CA glue from some of the brands available here - like Loctite, or goo made from acetone and plastic scrapings?
2. In the case I use CA glue, I've read somewhere that I have to seal the spruce top with shellac, but also put shellac inside the binding channel? Won't that stop glue from actually doing it's job - gluing?
3. In the case I use acetone solution, will it stick plastic to wood? I'm skeptical about that

Thanks

Goran,
Welcome to KGF and thanks for the introduction to the tambura. Is the darker wood a pick guard applied on top of the tonewood? What is the purpose of the greater spacing between the 2nd and 3rd string? When can we expect see photos of the tambura you're in the process of building??

-tommyboy

[chrysophylax]

Goran,
Welcome to KGF and thanks for the introduction to the tambura. Is the darker wood a pick guard applied on top of the tonewood? What is the purpose of the greater spacing between the 2nd and 3rd string? When can we expect see photos of the tambura you're in the process of building??

-tommyboy

Hi tommyboy

Thanks for asking more about tambura

Darker wood is american walnut (i think) and yeah, it is applied on top of the spruce. It can either be just glued on top or inserted into wood and flushed (like rosette on guitar). Purpose of this is decorative and functional since it protects very soft spruce from pick when playing, since tambura is played with very hard pick since strings are much stronger and higher in tension than on guitar, so soft guitar pick would just bounce off the strings.

It is tuned E A D G or F# B E A, depending on the region of the country, but lately F# B E A is becoming standard. Second and third string are spaced because first and second string produce same tone (like on 12 string guitar). Reason for this is because they have to be thin to withstand tension when tuned, so to produce better and stronger tone they have to be "doubled". Other strings are thick enough to be single.

I didn't really took photos of my ongoing project, but I have some pictures from previous projects



finished


Note: this is type of tambura called "basprim", there are 4 more different types, and when combined they make tambura band or orchestra..this is not solo instrument, though it can be used like that

If you're interested in the sound of this instrument, here's the good video (instrument in this video was made by famous tambura luthier Duško Rajković from Serbia)

http://www.youtube.com/watch?v=TCtFw6livLA

If you have some more questions regarding tambura building or specifics that differs it from guitar, feel free to ask :)

[tippie53]

The glues I use
Plastic to wood
Duco Cement or weldwood

Wood to wood glues
Hot Hide glue
Fish Glue
Tite bond

Wood to metal
CA

If you have to use CA on spruce you need to seal the joint with shellac to avoid staining

[Darryl Young]

Duco cement works well for the type bindings sold at Luthier Supply stores.......but I can't say for sure it will work with the plastic you selected. Be worth a try to test on scrap.

[tippie53]

I found Duco to stick all plastic that I found used in bindings.

[chrysophylax]

Like I said, I can't get Duco or any kind of similar glue here, that's the problem. I have to use either superglue or acetone. In the best case I can get some kind of automotive glue that bind plastic to metal, but I don't think it would be good for wood to plastic gluing.

If I use CA - do I have to apply shellac INSIDE binding channel? or just around it

[Darryl Young]

You have to apply shellac inside the binding channel else the end grain of the spruce top will wick in CA glue and stain the top.

Can you buy glue like is used to assemble plastic model cars?

[chrysophylax]

You have to apply shellac inside the binding channel else the end grain of the spruce top will wick in CA glue and stain the top.

Can you buy glue like is used to assemble plastic model cars?

Oh, I see. Won't shellac somehow mess with gluing properties of CA? Will the bond be strong enough? Somewhat easier option I think would be to make wooden purfling and glue it with Titebond, and then glue binding with CA, since it's all maple around it I think it won't stain like spruce, or I'm wrong?

I could probably get model car glue yeah, is it good for wood to plastic?

[tippie53]

where do you live ? We may be able to mail you some duco