Inlaid scratch plate alternatives

[dunbarhamlin]

Hi folks

I've reached the point where I need to decide what material to use for a Vega style inlaid scratch plate.

The incidence of sunken treble side in Vega mandolutes suggests that the inlay may be at fault (given the symmetrical bracing and body form)

I was wondering if a natural material would better integrate into the top (using HHG.)

I've considered burl inlay, which may provide the least resistance to top movement, but this would be at least as susceptable to pick or finger nail damage as the top itself - particularly if using a thin veneer to minimise acoustic and structural impact.

Am now looking at pressed cow horn plates (http://www.dick.biz/cgi-bin/dick.storefront/46f23a0c0008b39a274150f3360905ec/Product/View/831043) . Have any tried this? My thinking is that I can take it really thin, the HHG bond should be better than celluloid but the top protection and appearance similar.

Any thoughts?

Thanks
Steve

[Paul Hostetter]

Would the things on the Dick site be big enough? Opaque enough? 2mm is pretty thick, it might be like mica by the time you got it thin enough.

http://www.dick.biz/isroot/dick/Files/AbbildungGross/831089.jpg

I have some really thin but densely colored tortoise celluloid sheet that might be the ticket.

[dunbarhamlin]

Hi Paul

Yes, colour density and enhancement is something I'll need to investigate. I'd like to use natural materials if possible, but will otherwise have to find a European celluloid source with the hazmat restrictions on shipping from the US.

The rolled horn will be large enough, and price is reasonable enough for plenty of experimentation.

http://www.dick.biz/isroot/dick/Files/AbbildungGross/831043.jpg

For the piccolo (extrapolated from cylinderback mandolin and bowl back piccolo) I'll need to end up with a little over 3 1/2" by 4 1/2"

Am expecting to need to do quite a bit of tinkering re body depth and size before I get it right - so again, lots of opportunity for testing. Here's the first stab (camera is out at the mo, so this is just the topview composite from my plans):

[Bill Snyder]

Other than staying true to the Vega design (which may be reason enough) is there any reason to inlay the scratch plate?

[dunbarhamlin]

Hi Bill
I didn't use a scratch plate on the (non-Vega-style) cylinderback I use all the time, and (the way I play at least http://www.mandolincafe.net/iB_html/non-cgi/emoticons/sad.gif ) I find I could do with either a scratch plate or pick guard for protection (not as a rest)
So I will be experimenting with a floating guard for my body shape, but would like to stay close to the original Vega design for the replicas (and derivatives)
(Here's an old pic showing 'my' shape mandolin - non traditional):

[billhay4]

Steve,
Interesting looking instrument. Have you got a website or more pics?
Thanks,
Bill Hay

[dunbarhamlin]

Hi Bill

Thank you for the kind words.
Never got around to doing anything website wise (used to be one of professional hats, so...)

I was scratching around for just that pic - I have a few wip pics somewhere, but really just of the cylinder and back and top bracing. Will dig them out this evening.

Cheers
Steve

[billhay4]

Thanks, Steve,
There have been a few pics of cylinder backs in the cafe recently and they are fascinating instruments. I believe the guy who used to be partners in Rigel just had one up on the cafe.
Yeah, I found it: in this thread (http://www.mandolincafe.net/cgi-bin/ikonboard.cgi?act=ST;f=12;t=46795;hl=cylinder+back )
Bill

[dunbarhamlin]

Oo - I missed that thread - always fab stuff.
I do heat bend my backs rather than carve them.

For my Ridgebacks ('my' shape), I don't use Vega style bracing, but instead tall thin back braces and X bracing for the top.

The cylinder proportions are the same as a Vega.

[Eugene]

I wouldn't be too concerned about opacity. #Thin and translucent is a common feature of real tortoiseshell and some celluloid. #You can often see wood grain through old scratchplates and some golden-era builders actually lined reflective foil between scratchplate and soundboard. #I suppose whatever degree of opacity or translucence you'd like is fine.

Carlo Aonzo's Pandini has an olive scratchplate that I think is really attractive. I have a couple 19th-c. European pieces with rosewood scratchplates.

[Eugene]

So I will be experimenting with a floating guard for my body shape, but would like to stay close to the original Vega design for the replicas (and derivatives)
One thing that facilitates "floating" guards on 1908 and later Gibsons and inlaid/flush scratchplates on canted-top types is bridge height. #Yours looks to be set up with a lowish string height. #It's hard for me to imagine finding much room for hardware to "float" a guard.

[Bill Snyder]

... I do heat bend my backs rather than carve them...
Do you use 1 piece backs or are they two piece?
If two piece have you had any trouble with the glue joint when you bend them?
What kind of glue do you use for the joint?

[dunbarhamlin]

I use two piece backs, and yes, do sometimes have fun with the joint http://www.mandolincafe.net/iB_html/non-cgi/emoticons/smile.gif

Generally, all is well (I use a sort-of fox type form with a central long cramp over the seam which stays locked down until both halves are bent to shape) but when problems arise (all timing related - cooked too long or uncramped too soon) I use half width M/F cauls which hold and present the edge at the right angle to reshoot and rejoin (Sunburst helped me work this out a while back)

I've used Titebond until recently, when I switched to HHG. I have toyed with the idea of a high temperature epoxy for the centre seam, but not done anything about it.

Cheers
Steve