Official Luthiers Forum!

As a woodworker who is about ready to take the plunge toward luthiery, I have read a lot about building guitars. I admit to being a little overwhelmed by that most mysterious of tools, the radiusing disk.

I now understand the purpose and method of radiusing with a disk, after extensive reading about the topic.

So here's my question: it looks to me that serviced kits from Stewart-Mac or LMI come with the sides pre-bent and preradiused, and one glues shaped braces to the back and top using curved cauls. In other words, there's no need for a radiusing disk. Any comments on this?

I will probably continue on with guitar-building after my first kit, so I'm curious at what point you veterans got or made radiusing disks in the process of refining your techniques.

Any other thoughts would be welcome.

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Radius dishes really help. If you are going to keep building, get them now to take advantage of the numerous benefits they provide. Radius dishes combined with go-bar decks will eliminate a bunch of potential gotch-yas.

Doc Jeff my friend in addition to Barry's very good advice I can add this:

The Stew-Mac kit is unique in that it does not require an outside mold (although I would still recommend using one) and it does not require radius dishes. The sides are pre-radiused. It would be useful to you I believe to go to Stew-Mac's site, click on the kits, and pull up the dreadnought kit page. Under the "instructions" tab are free-for-download kit instructions that contain a plethora of great info. Although the cardboard form, waist clamp method that they use instead of an outside mold is lacking in my opinion much of the rest of the material is very useful including the finishing schedule which worked like a champ for me. Anyway I sense that you are a read-all-you-can guy like I am so this may be helpful to you.

The LMI kit will require an outside mold and radius dishes and the sides are not pre-profiled/radiused. But.... the LMI kit comes with an excellent DVD instructional video by Robbie O'Brien and Robbie is one very fine luthier and teacher. Robbie's DVD will teach you contemporary methods for guitar construction that you will likely use often for the rest of your guitar building life. I know that I have.

Regardless though a mold and dishes will be things that you will need going forward. I bought my radius dishes prior to my first scratch build and after building 2 kits - a Stew-Mac and a Martin kit.

If you don't want to make your own dishes Tracy at Luthier Suppliers (link above) sells nice ones in a variety of radiuses.

John Hall at Blues Creek (link above) also has excellent kits that can be customized as well. These kits in some cases use Martin parts like the neck for example. John's huge value-add over the Martin kits from Martin is that the Martin kits come with the worst instructional materials that I have seen....... John fills in these gaps and is available to you and happy to help with individual and personal assistance should you require it.

And of course there is always this motley crew on the OLF where all of us would be pleased as punch to assist you if you wish.

Although I have built other guitars before, I am using the radius dish for the first time with a Stew Mac 000 kit. As everyone said above it leads to more accurate work.

The main advantage I see when using a dish with the stew mac kit is for sanding the kerfing to the proper radius to accept the top and back. Their instructions say to use sanding sticks with wedges glued to the opposite end of the stick. I'm sure this works, but I think the dish would be more accurate.

Based on the answer I got in this thread (last couple of posts) viewtopic.php?f=10101&t=17071 I would sand both sides of the rim in the appropriate size dish to get the sides to conform to the profile of the dish, then put the kerfing on, and then sand the kerfing down. (If anyone with more experience than me disagrees with this please chime on. However, this is my understanding of the process)

I have dishes with a radius of 30' for the top and 12' feet for the back. The radius that stew mac put on their precarved braces is very close to these. I will sand the braces in the dish to conform to that before gluing them on the top and back using a go bar deck and the dishes.
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