F-Mandolin Lines & Curves

[Robert McCollam]

I recently purchased a set of plans for a Loars F-style Mandolin. These plans show the thickness of the two points (horns) sweeping up at the tips about 0.08 thicker than the general edge. I can not find any pictures showing this feature on genuine 1920's Loars mandolins.

Has anybody actually seen a genuine Loars with this feature?

Bob

[Jelle van Tilburg]

Hello Robert, 

Is it the recurve you are talking about? Never examined/ played a genuine Loar mandolin myself.

But found this website http://www.mandolinarchive.com/gibson/serial/75307 Lots of nice photo's there, maybe you can find what you are looking for.

Good luck!

[Robert McCollam]

Thanks!

[Ned Knepp]

I think it would be fairly hard to see in a picture unless it was focused upon the points.  I think it's probably what Jelle mentioned, a natural extension of the recurve. 

[Robert McCollam]

The Plan I have shows the thickness of the plate as 0.14" in general at the edge but 0.20" & 0.22" at the points 0.47" at the high point of the scroll.

[Ned Knepp]

High point of the scroll , as far as I know, is almost always designed to end up "higher' than the edges of the body.  It's a bit of a climbing ramp and one of the "tricky bits" in carving the F-style body shape. 

The recurve is basically a "ditch" at the edge of the body which curves up at the very edges of the body. The  points are outside of this "ditch" so following that part of the curve, it makes sense for the tips of the points to be a bit wider than the body at the sides.  You wouldn't have to do it this way but it makes sense to keep a gentle flow to the curve even it it flattens out some.

If I'm talking down to you, I  apologize but I would like to make a suggest based in personal experience; if you haven't built a carved top instrument, it might be more satisfactory for you to started with an A- style body to get some of the carving and shaping tricks down first. 

[Robert McCollam]

Thanks

I'm pretty well on my way with the F-style.

Bob

[William F.Eden]

Your doing just fine Robert. Do you already have the top glued to the sides? I have built 12 of them myself I carved mine with a 1/4'' drill and a 3/4" and a 1/12" sanding sleave and a 4" disk sander.Good luck with the rest of your build Bill........

[Robert McCollam]

Thanks,

Yes I already glued the top to the sides (Sort of following Simimoff's book) but I thought it would be easier to use my floating router set up (for guitars) to route the purflin & binding channel where I could reach it. I was able to get about 95% minus the scroll. I let the router float up and down for the wider/shallower purflin channel then locked it for the deeper narrower binding channel. Cut the scroll area and corners around the points by hand.

I was able to glue a b/w/b purfling in even around the scroll. I'd like to use real maple binding but don't think it will bend around the scroll. Any ideas in that area? (laminations, or cut, carve, file a solid piece ?????)

Bob

[William F.Eden]

You may try the Laminations but I think if I were going to use say curly maple for the bindings I would make them 1/16th" 60 tho thick and get myself a small piece of pipe  and put a small propane torch in the end  of the pipe to heat it up and try and bend the scroll first  have a spray bottle handy and just keep misting the wood as you go. As far as the other sharp carves go you just need a piece of pipe 2and a 1/2" to bend them that is what I used .You need to have your pipes 15'' long or so or you will get it to hot you can also rap that part of the pipe with some tinfoil were you are trying to bend so not to burn the wood.The purflings I always used 20 tho OR 40 THO.  black and white or what ever colour one at a time and super glued them on. Don't forget to do the 2/1/2" bend first on the scroll leaving enof bindings then add the button bend to that. Bill.......

[Robert McCollam]

Thanks again

[Robert McCollam]

Bill,

Well, I went out and bought 6" nipples 1/4", 3/8", 1/2" and 3/4" to add to the 1 1/2" one I used to bend the sides. I found that pre-bending with the 3/4" then going to the 1/2" and finally 3/8" seemed to work the best. I soaked the binding for 30 min. then sprayed after each time I heated & bent around the pipe. A small strip of sheetmetal bending strap was essential to eliminate burst fiber on the tension side. All in all a lot of fussing & patients was required.

I've attached pictures of the process & final bound top.

Again thanks for giving me the encouragement to keep at it.

Bob

[Ned Knepp]

Well, Robert, it seems that I WAS talking down to you. I'm sorry for that.   What you're doing looks good. I'm looking forward to seeing pictures of the finished instrument.