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Yes.sorry. When I did it the other way round the the chatter was really bad as I tried to sand.

So I've been pondering this a lot. I've laid two flat pieces of mdf, one on each bout and the angle is clear. The only other things I can think of is that I glued the top up in too low a humidity and now it's excessively domed or that as ken says, holding the top with elastic bands to take measurements is not accurate enough. The top does not appear excessively domed.with a straight edge across the lower bout there's about a 2mm gap at the edges.unless anyone has any bright ideas I'm going to stop bothering everyone with this, glue it up and see where I'm at and possibly thin the upper bout if I need to.. Thanks for all the suggestions.I'm definitely learning and understanding more which is the main thing.

Thanks Bryan that helps a great deal.... I think.... Still trying to wrap my head around the different mold and "sanding sticks." Off to read the latest comments and see if I can fathom where Mike is with this.

Mike we are still hanging in with ya and trying to help. Just having a lot of trouble translating what you have done into what I understand that's all.

So to back track to the last place that I can relate to here are some questions:

1) Regardless of the neck block squareness or angle is the top of the rim radiused to your desired top radius?

2) After this did you make pencil marks on the linings and neck block and flatten the upper bout with the shim removing pencil marks from the waist through the block?

I would be interested to know how you did these two tasks too please?

Moving on to the top was the top built to the same radius as the top side of the rim was sanded to?

For your upper transverse brace is it flat, slight radius, same radius as what you intended for the top?

I'm not all that concerned with the neck block angle although it is important, but not critical, to have it be square. How ever much it's off can be compensated for when fitting the neck and for an early guitar perfection is not necessary (you would be surprised at how many builders shun perfection on number 100....)(no insult intended to anyone but in our world we see everything that was not ready for prime time but was let out of a shop anyway....).

Now we also need to know more about the top and how it was built in respect to RH since you brought it up. If the top is a moving target so-to-speak and dynamically changing with RH swings fitting the neck is going to be a bear and this is one of the reasons why guitar building is completely intolerant of unstable RH environments during the building process.

Let's see what you come back with. Also I would greatly favor getting all the angles correct BEFORE installing the top. Lots of folks thin the top some for the extension fit but I'm not keen to do this in so much as I believe that upper bout structural integrity is critical to the well being of the neck angle over time.

I'm not sure if this factors in or not (it may just change teh actual angle on the heel) but I'll mention it anyway. It just occurred to me that if you shim under the heel block to raise the rim to level with the mold (using the sanding dish on top of the rim) you will have angled the side where it interfaces with the heel. The sides at the top of the rim will now be in a bit from "square," giving you a negative neck angle. could this be a factor?

_________________
Bryan Bear PMoMC

Take care of your feet, and your feet will take care of you.

You're a kind and brave man.

1. I said before (but not very clearly!) I sanded the top rim flat with sanding stick (ie. a flat piece of MDF with sandpaper attached), NOT radiused as i hadn't got a radius dish. I've since borrowed a jig and made a dish.

2. Yes, did this twice, once with a 3mm shim and then with a 6mm shim. I did it with the flat stone moving on top of the body not moving the body on top of the sandpaper as i found i got less vibration when sanding that way.

2 x UTBs and soundhole braces all Flat.

All other top braces 25 foot radius.

RH control tricky as my workshop is unsealed and, thanks to your posts, I now know that my hygrometers are rubbish. I've been using a drying cupboard which I'm fairly sure is pretty constant 35-40%. Workshop was very low recently, around 35 but usually around 55%. I'm not noticing any major movement of the top since bracing and nothing alarming coming in and out of the cupboard. The radius looks to be where it should be.

I'm not keen to sand the SB either but i dont want to waste peoples time with my confusing posts.

UPDATE.

I noticed when placing the flat MDF on the lower bout as in the picture that the lower bout was not completely flat so i flattened it out by pulling strips of sandpaper through. Fitted the top and held with elastic bands, now have a straight edge from the upper bout clearing the bridge position by a hair under 2mm. Is this enough?

I think whats causing me the trouble is the rims and back not being totally solid in the mould and not radiusing the top rim.

humidity gives me a real headache. did a quick dewpoint test with two fairly cheap glass lab thermometers. Digital hygro says 52%, ambient glass therm says 20deg C and I got Dew on the glass with the ice and thermometer at 1deg C. This would indicate I'm at 28% RH. It's 10deg C outside and raining and i've got a radiator and a dehumidifier on in a leaky shed.

Wow! I'll kick in my 2 pesos. You're making this way over complicated. You have dishes. That's all I use. I radius all my top braces to 25' accept for a 3" middle section of the UTB. I radius my rims in a 25' dish. That's it. I can see what might cause you some problems. You're not building in a mold. With what you are using there is a big chance of geometry chancing along the way. Not so much with a mold.

I hear you but i'd like to get to grips with the technique in Hesh's tutorial and if I sand much more off these rims there wont be much guitar left!

If you are worried about sanding the rim too thin, You could always remove the linings and install new material proud of the rim. Level the new linings to the proper dimensions then cover the gaps between the sides and top/back plates during the binding process. You could make up a little depth this way. the first step though is still getting a grip on the process.

If you do end up redoing the linings, may I suggest solid laminated linings? Once they are glued in, your rim will be much stiffer and help alleviate some of the headaches of not having a solid mold.

_________________
Bryan Bear PMoMC

Take care of your feet, and your feet will take care of you.

That is a good idea to avoid losing depth. I did use double laminated solid linings originally so wouldnt be a problem to install them. Any cunning ideas for removing linings?

+1!

In addition you are using so very many bit and pieces of different methods and building styles that I still can't understand what you are describing....

It also occured to me when reading one of your posts above where you talk about putting MDF on the rim which, by the way is a ????? moment for me.... that you saw some gaps and flossed to remove them. The stability of the rim is critical and this means how it's held as well.

The method that I describe in my toot has a dependency on an outside mold. You are not using one and as such all bets are off.

I'm been trying to help here all that I can but I have to tell you in nearly 10 years of helping folks via the Internet with often what we are talking about sight unseen on either end this interaction takes the cake for being the most confusing of my Lutherie career..... Not giving you a hard time, Mike, just trying to relate to you that your use of this and that from over there and over here has me as confused as someone who wants to get something done in congress.... (parliament for you fine folks).

For now I think that Danny may be on to something and he's a real bright guy too IME. He's suggesting that your rim geometry is shifting likley every time that you move something, flip it up side down, etc.

My method requires an outside mold OR a rim that is stiff enough to not need a mold such as double sides. You can try to adapt to what ever it is that you are ultimately doing but results will never be what they should be if things are flexing and changing every time that you move something.

There is nothing at all worng with the cool molds from Ken either, it's simplly a different approach and requires a different method for setting angles. But this is yet another example of your combining of methods here.

Your RH situation also sounds totally unsuitable for guitar building. We need fairly rigid RH control especially when bracing and for long enough periods of time for materials to acclimate as well. Guitar building will bite anyone who ignors this....

So don't get me wrong I'm not angry or pissed off or what ever but I am now saying that since you choose to use bits and pieces of many different methods at least for me I can't even understand where you are now!

Mike is there any possibility that there is another OLFer in your area that you can actually show what you have to? That would be my best suggestion for you now.

I'm going to go get a drink and I quit drinking 14 years ago too.......

Hey Mike, Hesh here again....

I think this is the issue, you are not using an outside mold that in my case holds the rim captive in both bouts and the neck and tail block are screwed to the mold for a very stable fixture.

Since I can't know how Ken advises folks to build with his molds he would likely be the best source of advice here now and I am sure that he wants so help as well. My method for flattening the upper bout, Martin's too and they did it long before me.... is not a good fit for what you are doing.

Oh Ken, oh Ken.....

Mike, I'm not sure I was clear enough on this point so I'll make it again. Work out the issues you have with achieving the correct geometry before you worry about regaining depth with proud linings. I'm not 100% sure how you are doing things or how you got to where you are. I wish I could help. Fortunately there are people here who can help you much better than I. I offered the idea of proud linings to be considered as an option once you have settled on a method. . .

Read the following with a grain of salt! I'm not sure I know exactly what you have to work with. I'm just going to tell you what I would try if I were where I think you are and had the set-up I thing you have. If anyone wants to come forward and say the following is a bad idea, please do. I'll not be offended, we just want to make sure there is good (peer reviewed) info here.:

If I understand correctly, you have a rim with the back attached and kerfed linings on the top. You are using an adjustable mold with a solid base and movable vertical dowels to define the shape. I would leave the back on, put the body (back down) in the mold such that the tail and untapered part of the sides are secure to the bottom. This should leave the heel block hovering above the bottom because of the back taper that begins around the waist. At this point you want to see how vertical the sides are at all points around the rim. Pay particular attention to the heel and tail block areas. If you are way off stop reading and hope someone else can help. If you are fairly close and just want to get moving on this project and take what you learned to the next one then carry on. . .

The rim shape as it attaches to the back may or may not be exactly the shape you intended with your mold but unless you plan of removing it and starting over. Use this as your new shape. Even if there is a little asymmetry, no one will really notice. Move the pillars of the mold in tight to the rim at the back to define your shape. Now ship up the back to keep the floating areas of the rim supported.

Now you should be able to see if the top surface of the rim is in good shape. The rim is supported from the sides and bottom so a straight edge can be used to see where you are and hopefully not distort the rim too much in doing so. If you are in good shape clean up the rim and move forward. I suspect you are not. If you have a lot of work to do but you feel it is salvageable, I would remove the linings an put in laminated linings. Three or more strips of thin wood bent to shape and glued into the rim near the top surface. If you have the upper parts of the rim tilting in towards the center of the guitar, you can clamp the sections of lining to the pillars of the mold and just use clothespins or similar clamps to clamp the areas between directly to the side. The linings will lend a lot of rigidity to the top surface of the rim and hopefully make surfacing the top of the rim doable with the dish on top. Or. . . with the back on and reasonably thick well glued linings, you may find that it is stiff enough to do the rim face down in the dish and follow Hesh's tutorial. YOU HAVE TO BE CAREFUL. Go slowly and don't use pressure, just support the rim so the sides are vertical and let the sand paper work otherwise, you distort the rim.

This has already turned out to be way longer than I intended I fear that people won't read all the way through this robbing us of the peer review. I'll stop now and see what people have to say (or I will go on forever).

_________________
Bryan Bear PMoMC

Take care of your feet, and your feet will take care of you.

Well Both my methods for the Mega Mold and our Masterworks molds are in fact based on the Martin factory machines and procedures. I won't post the links you can look at our instruction pages --- both edges of the rim are prepped while clamped securely to the mold (KMG Adjustable Mold and the Mega Mold have built in rim clamps for that purpose the Masterworks comes with the SS (super simple) clamp like Kinkead uses) But here's the problem -- the procedure is done complete "before either plate" is glued to the rim. We do show the contingency tweaking operation where the upper bout is sanded to get a perfect straight line plane if the complementary angles are off a little.

Frankly I am at a loss -- I know the above methods work consistently, the main reason being that a true position is established at the start -- that being a perfectly flat and level sound board edge. This is a starting point for angles and projections and most importantly a reference to make checks along the way.. Unfortunately, I could not even venture a guess regarding this assembly.

Mike can correct me, but I believe it is safe to say he did not use our prescribed methods/procedures.

_________________
Ken Cierp

http://www.kennethmichaelguitars.com/

Ken, Bryan wanna go drinking?

Ok.sorry for the massive confusion. Ken's methodology works great but lacking the fixture for flattening the upper bout I thought I would try an alternative method. on the other guitar I'm building using a solid mould,, heshs tutorial worked great but not on this one.

Bryan, Thanks, I have already done a good bit of what you describe. I think it is actually pretty close and my lack of ability to explain my situation had made it sound worse than it is. Hopefully once I've finished it I'll have stopped feeling stupid and may be able to post a picture or two!

I think I owe you all beer.

Mike wanna join us for a beer?

I assume that you are both Michiganders (and the ones who know what they are talking about in the world of guitar making and repair) that I will have to drive up there. I'll probably need to borrow a couch to sleep it off before I head back home.

_________________
Bryan Bear PMoMC

Take care of your feet, and your feet will take care of you.

Well whad'ya know! Hesh Lite!

Alex

_________________
"Indecision is the key to flexibility" .... Bumper sticker

"Michigan" Luthiery excellence goes without saying (just kidding) but for sure the Original Cottage Inn, walking distance from Hesh's shop is, in my opinion, one of the premier establishments on the planet for consuming Pizza and beer -- other items as well.

_________________
Ken Cierp

http://www.kennethmichaelguitars.com/

Ken's right the Cottage Inn is indeed a good time and it's 200 feet from the University of Michigan campus too so the beer flows quite well there.... burp....

Bryan you are always welcome my friend and I think that some of you guys would get a big kick out of seeing our shop too. Most of our clients stand there with their mouths wide open looking at 50+ years of instrument molds, half finished Lutes, other instruments that I can't even name but that were used to keep the cadence when slaves were rowing boats and that mean guy who looks a bit like Jihad John sands the mask would whip the rowers into line.... Yep stringed instruments were part of that too amazingly. We have old G*bson double neck bodies, lots of Stellas, hundreds of back and side sets, every imaginable size of fret wire, you name it we have lots of fascinating things in our shop.

We are in a historic building that has had the likes of Clapton and Lennon in it at times as documented by the local newspapers, etc. Hang out long enough and you may meet Jeff Daniels or see one of the original Stooges guitars. Lots of interesting stuff.

Anyway we like guests so if any of you guys ever want to see the likes of a very busy Lutherie shop that does high volume repair work here's an open invitation. I was thinking of having another open house this summer or spring too.

Lance works in Ann Arbor so he is close too and maybe we can pry him away from family and four legged friends when we have our open house.

Michigan's Gov. Snyder just bought a $2M condo within site of us but beyond that the neighborhood is pretty good....

Right across the street is a medical pot store and down the street is "Bong & Thongs" located next to the "Safety Girl" store that sells the stuff from 50 shades of gray.... Life in the city......that's why I live an hour away in the country......

When I was younger I loved this town a bit more than I do these days.... These days I'm content to be the neighborhood "lawn nazi" terrorizing folks with lesser lawns as I rev up my Gravely zero turn....

Life is great!!!

What was this thread about?

Mike, somehow I missed your post earlier. Sounds like you are getting a handle on it. Make sure you let us know how it all turns out.

Hesh, If I'm ever up in Ann Arbor, I will definitely look you guys up. I'd love to see your shop. We can call Ken and get some of that Original Cottage Inn !

Edit: Ha! Apparently just typing the word gives you the little eating icon. I wonder if Ken was able to type it without it changing to an emoticon was because he used a capital P in the word Pizza.

Second edit: It would appear from my test that capitol P does the trick. We should rename the one "kerfing" so that it automatically displays anytime someone types that out.

_________________
Bryan Bear PMoMC

Take care of your feet, and your feet will take care of you.

Well.good weather and a day on my own Without the young family.

first I re read how to do the dew test as I was sure I'd done it wrong. workshop at between forty and forty five. result. Then more or less did as Bryan described, got the sides at ninety degrees or very close. Decided that the body must be warping in some way when temporarily attaching the top and decided it might be because the back isn't sat on a radius dish then it's not well supported.cut a load of little wedges and put them under the upper bout where it wasn't resting on the mould. Decided it was as good as it was going to get and glued it up. It needed a little dressing of the fingerboard extention area but only minimal so I feel quite pleased now.also cut the neck heel angle to match and we're looking Good! Thanks all, apologies for the epic and confusing thread. I like and beer.

Good work, Mike! I hope this gets it done for you. Just ordered , already have the beer!

Alex

_________________
"Indecision is the key to flexibility" .... Bumper sticker