Official Luthiers Forum!

Hello,
I've been lurking around the OLF for quite a while learning as much as I can from the experience of the members here. I thought I might as well create an account and say hello and thank you all for unknowingly helping me through my first build. Before I go any further I would like to apologize in advance for what will no doubt be a lengthy post.

My first build was a dreadnought from an LMI serviced kit last year and am very pleased with how it turned out. It plays/sounds/looks great!  I'll post some links to several photobucket slideshows of that build at the end of this post. 
After some significant shop redesign and tooling up, I am now in the process of building my second. This one is a scratch build with materials sources from various places. This guitar is a dreadnought sized guitar (approx. 16" lower bout) but has a shape similar to that of a Gibson Jumbo. I basically took the plans for a J-200 and a dreadnought and blended the lines of each to get this shape. I couldn't build a "true" Jumbo due to the limitations of the wood I currently had on hand. Only had one back set suitable for 17" wide body and I didn't like it so much... So I made a "custom" shape mold that worked for the wood I wanted to use.

Last night I glued the back on to rims, so this one is really starting to take shape quickly. I started it just after Christmas.

I have a question regarding top thickness:
I've recently jointed and thicknessed an Englemann top for this guitar.
I know that Englemann is usually regarded to be not as stiff as some other species of sprice but (keeping in mind my limited knowledge) it seems like a real stiff top, when I compare back to the my kit build. The kit had a sitka top that was thicknessed to .125 for me by LMI.
I brought the englemann top down to .105-.100 range and even at that thickness its notably stiffer than the sitka top was at .125" I still have the soundhole cutout from the sitka top at .125 and it's like rubber compared to the soundhole cutout of the englemann top. I know this is not really good test but it reinforced my belief that this top IS much stiffer than my last guitars' top.

Although I feel it is a stiff top I am a little worried I took it down too much. Based on things I've been reading it seems the lower bound for an Englemann top is around .110" My REAL concern is that in the process of scraping/sanding the rosette (rosewood) after I installed it I ended up thinning the top even more around the soundhole. It's about .090-.095 in the immediate area around the soundhole but still within the .105-.100 range everywhere else. I'm afraid of the soundhole distorting under string tension being so thin. Having seen, heard and played some really nice guitars at the Montreal Guitar show this past summer (I'll certainly have to visit that show again this year) with a soundhole doubler, I'm strongly thinking about adding one to this top to help reinforce the sound hole. I had this in the back of my mind anyway as I like the look of it, but it seems now I have a structural reason to do it as well..

Based on the above information I have a couple of questions:

- Who feels this top is too thin? Should I just put this top aside and use it for a smaller body guitar (ex. OM?!?) and joint up a new top (I have plenty) for this larger (Dreadnought/jumbo hybrid) guitar?

- If I decide to go with a soundhole doubler, should it be glued in cross grain or with the grain?

- Would making stronger braces for the soundhole area and upper bout be a good idea here? What about using A-Braced instead of the transverse braces I was planning on using?!?

Cheers,
Chad

Links to pics from my first build:
Slide Show 1:
http://s148.photobucket.com/albums/s35/chad_goobie/Guitar%20 Build/?action=view&current=1175109492.pbw

Slide Show 2:
http://s148.photobucket.com/albums/s35/chad_goobie/Guitar%20 Build/?action=view&current=1175110297.pbw

Slide Show 3:
http://s148.photobucket.com/albums/s35/chad_goobie/Guitar%20 Build/?action=view&current=1175110856.pbw

Slide Show 4:
http://s148.photobucket.com/albums/s35/chad_goobie/Guitar%20 Build/?action=view&current=1176920074.pbw

Slide Show 5:
http://s148.photobucket.com/albums/s35/chad_goobie/Guitar%20 Build/?action=view&current=1176920208.pbw

Slide Show 6:
http://s148.photobucket.com/albums/s35/chad_goobie/Guitar%20 Build/?action=view&current=ad4b1906.pbw

Slide Show 7:
http://s148.photobucket.com/albums/s35/chad_goobie/Guitar%20 Build/?action=view&current=5cf5e1e5.pbw

Slide Show 8:
http://s148.photobucket.com/albums/s35/chad_goobie/Guitar%20 Build/?action=view&current=5db0d045.pbw

Slide Show 9:
http://s148.photobucket.com/albums/s35/chad_goobie/Guitar%20 Build/?action=view&current=55ae4614.pbw

Slide Show 10:
http://s148.photobucket.com/albums/s35/chad_goobie/Guitar%20 Build/?action=view&current=e75bf3f1.pbw

Slide Show 11:
http://s148.photobucket.com/albums/s35/chad_goobie/Guitar%20 Build/?action=view&current=9ebcecb5.pbw

Slide Show 12:
http://s148.photobucket.com/albums/s35/chad_goobie/Guitar%20 Build/?action=view&current=79289384.pbw

Slide Show 13:
http://s148.photobucket.com/albums/s35/chad_goobie/Guitar%20 Build/?action=view&current=15f2e41f.pbw

First we have no way of knowing if your top is too thin. to determine that we would have to have it in hand. I can tell you on a 16" LB guitar I would not have taken it down past .115 before bracing (now that is just instinctive not subjective as I never handled top)

A sound hole doubler is not a bad idea. That said standard sound hole "A bracing" would likely be just fine. Here again I don't have the top in hand so this is no easier to answer in relation to your top.

In my opinion if you go with a doubler it will be a stronger reinforcement if you cross the grain. But considering you are doubling the thickness anyway I don't think it would hurt if it was matched grain direction.

Thanks for the quick reply Michael!

I was expecting the "No way to tell without touching it" response and that is completely understandable as it really is impossible to know just by written description. I really wish I knew an experienced builder in my area (Ottawa, Canada) that could give me the thumbs up (or down) on this decision, but alas.. I don't..

I know that I am bordering on the thin side according to numbers I've found in archived posts and the comments I've read, like yours for example where you say, "I can tell you on a 16" LB guitar I would not have taken it down past .115 before bracing" that keep making me second guess about using this top. It's the numbers that are scaring me a little not the feel of the top.. But as I've said, I'm inexperienced at this craft so I'm constantly second guessing my judgement anyway.

Thanks again for the reply!

Cheers,
Chad

I just noticed that the picture links I posted don't work. For some reason there is a space between "20" and "Build" that needs to be deleted.
Sorry about that

Chad, Welcome to OLF.  I couldn't get your links to work.  Use the little world with a link on it in the reply box to post your links.  That will make them acitve links.  If you are using a Mac, I suggest using the Firefox browser.

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Waddy

Photobucket Build Album Library

Sound Clips of most of my guitars

Chad I forgot to bid you welcome...Shame on me.. Glad to have you with us.

Now I assume this guitar is for you. and this is not on some out of this world exotic wood. That said I would mo discount the top as of yet. I would brace it first and get a feel for how it is after bracing. A lot of good guitar have Englemann tops .100 thick. If at that point you feel it is too floppy then it will be time to maybe build a different top and put that one on a smaller body guitar at a later date.

One more thing If you like the jumbo shape but in a smaller body take a look at the Med Jumbo and Small Jumbo plans in the "library of plans" at the top of the page. The MJ is 16 1/4" LB 21" long the SJ is 15 1/2" LB 19 15/16" long. you might consider one of them for the future. By the way Ameritage makes a case custom fitted to them or at least the SJ is currently available and the MJ will be available later this year.

Welcome Chad to the OLF.

As you have heard we can't know how stiff this top is from a thickness measurement.  But you are right that Engleman is not known, generally speaking, to be one of the stiffest spruces.  Of course there will be exceptions.

Going back to pulling from Occums razor for the second time today..... I would not use it.  You sound like a careful and concerned builder and this says to me that you wish to do great work. With this said, why take a chance?

Also - it sounds to me like the kit top was exceptionally floppy and probably not a good gage going forward.

Again welcome to the OLF

Welcome Chad from Canada.

Goobie is a Newbie!   

Good luck getting those pictures working, I tried too to get your bucket to work, no luck.....

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http://www.dickeyguitars.com

Based on what you said, there is just no way to know. I measure stiffness by placing the top on a 18" span and adding a weight and measuring how much the top deflects. Do a search and you can see some setups.
That being said, from what you have described in comparison to your sitka top, you will probably be fine.
I am assuming that this guitar is for you. The worst case is that you'll have to replace the top in a year or more. That's not as bad as you might think and you'll learn a lot from that.
I don't think that will be the case.

_________________
"An adventure is only an inconvenience rightly considered. An inconvenience is an adventure wrongly considered." G. K. Chesterton.

Thanks for all the replies and warm welcome!
Bruce, as you can imagine I've experienced quite a bit of wordplay on my name over the years!

To address some of the points you guys mentioned,
This guitar will actually be a gift to someone close, so while I'm not concerned about "getting a bad name" if the something goes wrong with it down the road, I obviously want the person to really appreciate and enjoy this guitar for years to come.
Hesh, I'm probably a little over cautious (if there's such a thing) with my building. But I figure the more cautious I am now, the better I'll be in the long run.

I'm here in the shop right now (gotta love wireless routers!) with another top set in my hands.
I think I will do what was recommended and both brace this top and see how it works out AND prepare another top just in case I don't like it.

I did take a look at the MJ and SJ plans at one point and in hindsight probably should have ordered them, but I really think this one will work out very well with the shape I have come up with.  I'll try and post some pics of this one soon.

I'll try and post those links again if I manage to figure it out.

Cheers,
Chad

Ok, here's a link to all the slideshows in Photobucket. I'm too lazy to repost all 13 one by one again 
There are 3 pages of them, If you want to see them in chronological order start on the last one on page 3.

The link

Cheers,
Chad

That works.  Nice set-up.  Nice looking guitar too. Good slide show/shows.

_________________
Waddy

Photobucket Build Album Library

Sound Clips of most of my guitars

Welcome to the forum Goobie!

Very nice looking guitar. Looks like you took your time and did the finishing right also.

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Reguards,

Ken H

Hi Chad, welcome to the OLF from one Canuck to another.

I know of one luthier who is close to Montreal. There's a moderately well known luthier in Chelsea Quebec you might try looking up. His name, Sergei de Jonge. He'd be able to tell you a thing or two about that top of yours

Also, lesser known guitar maker and OLF member Alain Desforges who lives in Curran Ont, (about 70km's east of Ottawa), you can try PMing him for some possible help.

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"There's really no wrong way, as long as the results are what's desired." Charles Fox

"We have to constantly remind ourselves what we're doing....No Luthier is putting a man on the moon!" Harry Fleishman

"Generosity is always different in the eye of the person who didn't receive anything, but who wanted some." Waddy Thomson

Hi Rod,
I know there are a couple of respected luthiers within a short drive of me. Sergei being one of them. I've been itching to take his 5 week course for over a year now.. But it's proving next to impossible to get that much time off from work to do so. So I decided to try and learn on my own using books, internet and videos. I did have the opportunity to meet him last summer at the Montreal Guitar Show...His work is phenomenal and seems like a nice guy as well. Chelsea is only about 30 minute drive from where I live, but I'm a little hesitant to just contact people and ask for help. I don't want to bug people when when I'm sure they are busy

Thanks for the kind words about the guitar! If that one didn't turn out as nice as it did, I would probably not have been as keen to start another so soon

Ken the finish was a very scary process for me.. I have next to NO finishing experience (other painting a fence, LOL), but thanks to information I've found here and other sources I managed to pull it off with good results. I think I would like to get away from nitro eventually due to health risks etc.. But for now I'll probably stick with it as it worked for me so far.

Cheers!
Chad