Mike Floorstand - Posted - 03/11/2015:  15:55:15

Couple of questions about skin heads. First, I recently bought some calf skin vellums, they look like they have quite a bit of transparency on them - see example on left of photo below. But after I'd soaked one and fitted to the rim, it has dried mostly opaque, with a much smaller area of transparency than before it was soaked (fitted example on right of photo). What causes this - and is there a way to maintain or even increase the amount of transparency?

Second question relates to these calf skins being very thick compared to skins I've used before (the guy I bought them from makes them for drums so I guess he wants the extra thickness). With I suppose a fairly predictable effect on sound - a flatter tone. (One less predictable effect was that the extra thickness seems to be acting like a shim when tightened the tension band, and I've had to swap my previous 1/2" bridge for a 5/8"). My question is, can I reduce the thickness of the vellum after fitting, perhaps by sanding one or both sides of the head?

Thanks

jbalch - Posted - 03/11/2015:  18:30:15

I have never experienced a hide changing color (becoming more opaque) just from being wet & drying.  I can't explain that.

Regarding thickness, you can definitely sand (or scrape) the hide to reduce thickness.  I think I would do so before mounting - rather than afterwards. Dan Knowles discusses that on his thread here (scroll down a bit):  banjohangout.org/topic/251124/134

I think scraping the hide might create a more opaque appearance.

blm10jn - Posted - 03/11/2015:  18:56:39

1: Vellum is very thin so if you bought thick hide heads you do not have vellum.
2: If you bought from Stern you can order how thick you want in thousandths and the surface finish but sounds like you bought from someone else
3: There may still be a lot of moisture in your head. That could be the cause of the color.

banjonz - Posted - 03/11/2015:  19:00:22

Those vellums look like the ones available from Elderly Instruments. These are the economy heads (in both goat and calf) and do vary. Out of the two I would choose calf skin over goat. I have had too many issues with goat heads.

chucksiler - Posted - 03/11/2015:  20:45:56

I have only mounted a few heads, but I like the sound & feel so I keep fussin' with 'em.

One I mounted was too thick after putting it on one of my cheaper banjos, it was stretching the flat hooks at the tension hoop trying to get it tight and could not get any volume out of it. 

I dismounted it turned upside down and sanded it to just less than .010. It was a pain. But with upgraded flat hooks, now I like It.

Here is a pic. of another one that turned a little opaque on the very edge at about 6 & 12 o'clock. I'm not sure why?