Adventures in amateur lutherie......

[sebastiaan56]

Well.. its finished for the time being. This is number three for me and there are still a few things to be done, mainly acquire a more solid and attractive tailpiece and touch up the finish on the neck block. The neck needs a bit more shaved off it but it has a carbon fibre truss rod (thanks Allen) so Im a bit reticent to go to hard. I didnt do as good a job on the fret ends as I originally thought. I also thought that the edges of the rosette would come up nice and crisp if i used the fibre purfling..... I now know better

Its tuned CcGgddaa which gives it a richness and some interesting effects using down/up picking regimens. Its loud but mellow, with good sustain, it will be interesting to hear it open up. It is very nice to play.

The process has been a bit laboured. The original conception was a copy of a 17C Dutch cittern but its been through a lot of evolution. I originally set the neck at 8 degrees and this led to a bridge height of 38mm, lets hear it for bolt on necks. After some adjustments its now 25mm but im not going lower as the soundboard wont let me. This has also meant some bridge dents in the soundboard , you live and learn. The WRC is very soft and shows every encounter with anything harder.

The body and neck are New Guinea Rosewood which chips out the moment you show it a tool, and bends/cracks after extended manipulation. The soundboard is Western Red Cedar with some lovely silk, the headstock plate is Figured Blackwood. the fretboard is Cooktown Ironwood, the bridge is Rock Maple stained black, the bindings are from our own TJ Spittle. Its finished in TruOil, 9 coats, over Hard Shellac.

Honest feedback please.









Sebastiaan

[Dave White]

Sebastiaan,

I think that's pretty darned good for your third instrument. The thing that to me would be most important at this stage is the sound - just by making more instruments, the "cabinet-making" side of things gets better and better but it's not always as easy to find the magic tone you are looking for. I like the look and design and the wood combinations work well together. What scale length is it? I'd love to hear a soundclip and see pictures of your bracing design.

What did you use to cut the rosette channel and how did you level the rosette? I find it easier to level rosettes using a belt sander (or thickness sander) and then do final scraping with it pretty much levelled - this gives me a cleaner purfling edge. But the real key is to have a clean edge to the rosette channel. I use a laminate trimmer with a spiral downcut bit.

Unless you are a neat picker cedar will show every mark. It may be just the photo glare but I think I'm seeing the first crop of pick marks above the soundhole. I'd be tempted to put a clear pickguard in vulnerable areas then you can play away with merry abandon. It's interesting to analyse peoples pick style from where pick marks appear - a bit like reading chladni patterns. Some people need the guards in the exact opposite places to where they are traditionally put.

I'm interested in the New Guinea Rosewood as I've seen a number of references here on the ANZLF forum to how hard it is to bend. I got a set of curly narra from Bob C and apart from a few areas where the curl meant it would crack if you looked at it hard enough I didn't find it that difficult to work with. Is this the same stuff that you guys call New Guinea Rosewood? Based on the one guitar I have done I quite like it and it seems to sit somewhere in the Mahogany/Walnut tonal area.

Well done again!!

[Allen]

I quite like the look of that Sebastiaan. That's a very attractive combination of woods, and you must have learnt heaps during the evolution of this instrument. It has a very nice vintage look to it, that I think will only improve with use. Those dings that you've got in the soundboard are just the start to a great "distressed" look. I'd be happy to add that one to the instrument rack.

I've only used Western Red Cedar on one instrument, and like you, I found that it needs to be handled with kit gloves. Everything needs to be padded, and make sure that even small shavings don't get under the sound board when your working on the back. I did find that once the lacquer was on it that it really helped though. It's also the first time that I got to steam out some dings that just seemed to appear anytime I worked with it.

The rosette is a nice design, but does look a bit fuzzy in the picture. I've found that if I set the rosette just a hair deeper than the sound board, I don't have to sand at it so much and they end up a bit more crisp looking, rather than taking the rosette down to the level of the sound board. This is also important when you inlay pearl. It's just so hard that its really difficult not to have the sound board want to undercut when you try to get the pearl level.

I also found that the New Guinea Rosewood to want to tear out if you came at it in the wrong direction. I've not bent it yet, so thanks for the heads up. There is heaps of it around the Cairns Woodworkers Guild, and it seems to vary widely in it's consistency. Some is almost punky, while another piece will be hard and smooth. I still love the look of it, so will continue to use it when I find suitable pieces.

As far as I know Dave, Narra is the same as New Guinea Rosewood.

And some interior shots would be nice. It's not a guitar, so the bracing is going to be something new for me.

[Taffy Evans]

Nice looking little instrument Sabastiaan, nice work. I'm just trying to work out how many guitars I have built out of NG Rosewood, must be 10 or so now over the years, 12 if you count solid bodies. Also some mandolins and dulcimers. I have just finished a "000' using it. I have quite a big stash of it. I just keep going to the timber yard and buying up all the 1/4 sawn stuff. I thought that it was close to mahogany in some ways, but not so forgiving when working with it. I dont go to close to the final thickness with machinery due to the tear out at times, but finish with the thickness sander and scraper. I found that after soakig the sides and bending them they come out thicker than when I started, so I thin the sides more than other timber and find it seems to swell up to the the thickness I want. This would make it easier to bend. I use it in between building guitars with more expensive timbers. The other problem I find is filling the grain, but Allen seems to have that sussed, I'm trying the "egg mix" over the weekend.

[Paul B]

That's looking great Sebastiaan, I want to have a crack at building a mandolin as soon as I get Grahams book and finish the guitars I'm currently working on.

Narra and New Guinea Rosewood are the same thing, it's also called Solomon Island Rosewood, depends on where it comes from (I think the Solomon Island stuff is darker redish in colour due to the soil differences). I've made a couple necks from this stuff and it seems great (Gilets use it for necks too), also used it for kerfed linings and headblock on my latest. Great tap tone and cheap as chips 'round here ($9 for a neck blank). I bought a wide board of the stuff for back and sides but it was kind of a "baby shit brown" colour when planed and not very attractive at all, so it gathers dust...

[Kim]

Sebastiaan,

I think this is a wonderful looking mandolin. I like the finish and the style, it seems to have the nice warm glow and mojo of a well cared for antique instrument.

Now, if we can just coax a sound file

Cheers

Kim

[ozziebluesman]

Hey Sebastiaan,

Thats a great little mando with a real vintage vibe. I too like the warm colours of the WRC anf the NG Rosewood and the True-Oil over hard shellac has finished off the instrument beautifully.

Thanks for the pics

Cheers

Alan

[WaddyT]

Very nice, Sebastian! That's the nicest vintage looking mandolin I have seen.

[sebastiaan56]

Thankls for the great feedback folks, truly appreciated.

Dave, I take your comments on sound on board. I like the more mellow sound of the round hole over f holes. Ive gat an oval hole underway and that seems prettier to me. I also like slightly deeper bodies, maybe my ears are changing as I get older.

Allan, thx for the tips on the rosette, after I flooded it with cyanoacrylate it did get rather hard to sand and yes the WRC can be a pita. I cut a lot of it by hand, Ive been loathe to use my big router, but have a larger gamil type tool in construction.

Taffy, Paul, There seems to be a lot of NGR around the east coast at the moment. In my woodworking class there are people making boxes, bedheads etc from it. I found it easy to fill with Zpoxy, it really does take a finish well. There is also a lot of variability with the stuff, some pieces just chip out. I have a piece on the lathe at the moment that is threatening to take a roll of 80 grit..... Interesting the comment about it swelling, how do you cut it Taffy on the quarter or flat for the sides. I like the look of the flatsawn much better.

Kim, Alan, Waddy, thanx, I will get a sound file going, now all I need is a mike, guess the one for skype wont do .....


Sebastiaan

[graham mcdonald]

I would worry in the long term about a 25mm high bridge on a flat (or brace-arched) soundboard. That is putting on a lot of downwards force which is not good for it. I would suggest planning for no more that 12-13mm bridge height on a flat soundboard which usually means no more than a degree or two back angle on the neck

The bridge also looks a bit massive, though it would be worse if it were ebony. If you have one that high it would be worth experimenting with a couple of the Red Henry style of mandolin bridge (based on violin bridge theory) or try a single footed but thinner bridge (around 6mm) and see what they do to the sound.

I find the best way to work neck angle/ bridge heights/ soundboard arch height etc is to draw the whole thing out as a side view plan, especially when building something new like a mandola

cheers

graham

[Hesh1956]

Beautiful instrument Sebastiaan my friend and I think that you should be very, very proud!

When I build with WRC it dented in places that I have no idea what caused it........ It's very soft stuff but it does make us mindful of protecting the top on all builds which is a good thing.

Outstanding and beautiful instrument Sebastiaan!

[sebastiaan56]

Hi Graham,

The soundboard and the back both have a 20mm arch on them, the brace is a single transverse brace like the A4 Gibsons. i agree the bridge is a bit massive, I'll have a look at Red Henry's page again. Thx

Dave, the string length is 460mm,

Thks Hesh,

[Taffy Evans]

Sabastiaan, my sides are all on the 1/4.

[Craig]

I'd like to agree with what others have said in that it has a wonderful warmth about it. A fantastic aged look.

The true oil has worked out so very well too Sebastiaan . Could you tell us how you went about puting it on ?

Very cool !

We are a fortunate lot to have Graham with us to offer his expertise

Cheers,

[graham mcdonald]

I wasn't sure whether it was carved or not (I thought is was just flat and an arch put in with bracing) The bridge height will not be so much a problem structurally, but having too much down pressure on the soundboard can restrict the sound. I can't tell what your break angle is over the bridge from the photos, but something between 14-18 degrees seems to be optimum. Much less and it won't drive a carved soundboard optimely, much more and I suspect the arch is compressed a little and can't resonate as freely

What thicknesses did you are the WRC to?

cheers

graham

[Bob Connor]

I'll have to agree with everyone else and give the thumbs up on this one Sebastiaan. It's got a lovely warm feel about.

I'd like to hear a soundclip as well if you can do one.

[matthew]

Sebastiaan I hope you're getting over your flu.

I know zip about Mandolins, but yours has a friendly "play me" thing about it. The body just hangs there suspended like a drop on the end of the fingerboard. It also appears to have a very subtle asymmetry in outline that I really, really like. Maybe It's just the photo. I think asymmetry gives an instrument a soul.

I too find cedar a bastard of a wood to work on with a knife. My bass's shoulder purfling is less neat that i had hoped. One day I'll make a spruce top, if i can find any big enough!

[sebastiaan56]

Mathew,

Maybe Monday we will find you a bit of Spruce!

Thx Bob, when I get a mike I'll do a sound clip.

Graham,

3mm at the edges, 5mm in the centre, the break angle is 26 degrees. All a bit in viola territory i know, the next one will be better planned. Is there an optimal break angle for each string length? Im thinking of a Mandocello.....

Also is there an optimal length to width ratio for the soundboard of an instrument? I saw a walking stick guitar on the MIMF recently Im intrigued as how it would sound.