Wednesday, October 19, 2011

topping along

 There are lots of ways to glue the top of an instrument on. The clamps I use for violins are very specialised for quick clamping because using hot hide glue over the entire surface of both components is challenging at speed....with absolute accuracy. With that glue there is no time for adjustment before it gels.

For guitars, some people use elastic substances- cords, tapes etc- hooked over screws on the sides of the mold, backwards and forwards over and over to cover the surface. Some people use dozens of individual spool clamps, while some use a curvable plate overlapping the top by a margin big enough to screw it down.

What I did here was more akin to the last example than to the others. If the top fits all the way around, without wayward bits that have gaps, then very little pressure is required to clamp it. You really only want the minimum of pressure needed to squeeze out excess glue because the top should want to sit exactly where you put it. I used 50mm bugle headed screws in a battery driver with the clutch set carefully to slip on very little pressure to make sure I didn't get too enthusiastic with the tool.

If I decide to make more guitars I might make a more formal arrangement than the separate pieces in the pic above. I may have to anyway for the back, which has much more fore and aft curve, particularly at the top of the long arch.
The little blocks on the inside of the mold are there to hold the sides about 20mm above the top of the mold, against the clamping pressure. This view from underneath is a luxury that won't be available when the back is glued on. I can check whether the linings and blocks are actually pressed to the plate, but that won't be possible next time. So, I've already dry fitted the back with temporary clamps to reassure me that the fit is good, and I know when I glue the back on 'blind' that it should be all good in there.


  1. It is great to watch the build in, almost, real time. I'm really surprised at how quickly it is going. Is this pace based on 14 hour days?

  2. Hi PR, glad you are enjoying it! Actually, inevitably, once I started this thing work started coming in, and as so often is the case, a bit of pressure helps me get into a higher gear. The less time I have, the more I seem to able to find...or something. But I'm not rushing it, I just go with the flow when I can.

  3. I recognize the high gear mode. Sometimes a project will just not wait.

    A new look for the middle thing - don't mean to be persnickety, but the font is pretty small for old eyes.


  4. Thanks for the input about font size MB. Duly acted upon. I was having trouble with 'dynamic views' as an option. It has stopped working for me, so I tried the new view format, having been reassured that I could 'revert', but it wouldn't after I found the new format couldn't support my blog roll and label cloud, and members. So I started again, without much attention to detail!

  5. Hi Rob,
    Watching the progress and a question came to mind that you may have already addressed but here goes.
    Is this the first guitar you have made? If so did reading provide any direction over what you obviously know about instrument making or are the techniques so similar it matters not.

    BTW I lost all my blog subscriptions the other day except for "the middle thing".....thank goodness and I too don't like the new look.


  6. Hi Mike
    sorry you aren't happy with the new look.
    Yes I've accumulated quite a few books over the years (mainly on archtops and classical guitars), since my interest in making instruments was pretty much focussed on guitars before I had the opportunity to train in violins. Even then there were a few guitars being made by others around me when that happened. The quality of resources available is why I'm not trying to do a 'how to' blog, and haven't bothered with a set of pics for flickr.
    I'm just thinking out loud is all, and hoping someone enjoys it.