O'Brien Guitars - Luthier Tips du Jour- Top Bracing

Luthier and Instructor Robert O'Brien discusses his acoustic guitar top bracing glue sequence

[@14moldyhamsandwich]

it took me 4 years to pay for my braces. now i can smile in public

[@gallopinghost74]

Robert, thanks for taking the time to share your knowledge with all of us. You're a really fantastic instructor and the amazing detail you present in these videos have filled in so many of the gaps missing in the few luthier books available.

[@OBrienGuitars]

The go ahead and subscribe as I already have a youtube channel. Look for O'Brien Guitar or just click on the rosette icon in the upper right corner of all my videos. You can also go to my website and see all my videos there.

[@henrynagle2865]

Excellent video! So much good information. Thanks very much!

[@OBrienGuitars]

Thanks for watching. Glad you enjoyed the video.

[@paulwaldrop]

Thanks for the great instruction videos Rob. Getting ready to start working on my first acoustic.

[@OBrienGuitars]

Thanks for watching. Glad you found the video useful.

[@brandonclayton7251]

I enjoy watching how people do things differently, yet still achieve similar results. For instance when I brace a top, the first thing I install is the bridge plate.

[@OBrienGuitars]

@themurkar The braces are radiused in the dish, they are then glued to the soundboard or back in the dish as well.

[@OBrienGuitars]

Yes, the upper transverse brace as well as the x brace are notched through the kerfing.

[@juliantaylor7663]

on my first guitar (Gibson j45) it was a real pain trying to line up the braces cause on the plans it showed all the main top braces going through the kerfing, will it still be structurally safe just to have the braces you mentioned into the kerfing and shortening the others so they stop just before the kerfing? one last Q for the wide brace at the top can I use an off cut from the soundboard cause I was taught to thickness after inlaying the rosette and cutting out the top thanks for all the vids as always

[@lazn9863]

i recently took apart my favorite guitar a laminated yamaha 441bl (laugh all u want it kills any martin taylor and gibson i've owned and played). What i noticed was that the top as soon as i took out the binding practically fell off , the glue was minimal and was essentially unglued due to thousands hours of playing. The top was practically held in place ONLY by the binding. The guitar had a phenomenal sound and sustain...

[@OBrienGuitars]

My classical braces are completely different. I just finished one today where the braces ended up at a height of about 4mm. It all depends on the stiffness of looseness of the top I am working with.

[@OBrienGuitars]

@t0umart0u I have not but kent Everett has a voicing dvd and it is very good. It is available at apprentice publishing

[@garyphelps9123]

IS THERE A SITE WHERE I CAN VIEW THE DIFFERENT KIND OF TUNERS I WANT TO DRESS UP MY D45 THANK YOU

[@massnb]

I see. Thank you for the reply. I'm working with a Carpathian spruce top, thicknessed to an average of 2.3mm. I know every plate is unique, but would you have any numerical advice for that? I'm using a Torres style 7 brace fan pattern, normal cut-off braces. I'm sure it's difficult to say anything without feeling the wood, but anything is appreciated. Thank you very much.

[@massnb]

Thanks for the video. How do your dimensions for classical guitar braces compare to these? Still 6.5 to 8mm? And what would be the range of the height of classical guitar braces? Thank you very much.

[@SIRONEDRAGON]

cool : )

[@gordonsteeves9950]

thank you Robert for a look into the wonderful world of top bracing, a couple of questions, 1) those fiberglass rods that you are using, guess i got up to early this morning, but how are they fastened to the bracing?? i seem to be missing something there 2) and yet another huh?? from this newbie wanna be acoustic guitar builder, using a radius dish to sand your bracing, have you already used your radius dish to sand the under side of the top, and are now matching that shape by sanding the braces?? thanks again for the info, guess i had better get another coffee and re watch this vid :)

[@OBrienGuitars]

Gordon, the fiberglass rods are just placed under tension into the go bar deck and they hold the brace in position as it dries. The braces are radiused and they mold or shape the top as they are glued in. Hope this helps and thanks for watching my videos.

[@flaviodelisa]

Obrigado pelo vídeo Quero saber, se este tipo de leques, serve para viola caipira.

[@OBrienGuitars]

Tem gente que usa sim

[@user-gy1qb7oo5w]

Hola!! Estoy construyendo mi primer guitarra acustica. Y ahora md doy cuenta que pegue mis barras tonales en el lado opuesto, digamos hacia el lado de los graves. Creo que interprete mal mis planos,. Esto afecta el sonido de la guitarra? Gracias...

[@OBrienGuitars]

Estará bien, pero intenta no volver a hacerlo en la siguiente guitarra.

[@Fazman81]

What do you think about unscaloped bracing Robert? Have you ever tried it and do you think there are any benifits? I follow a lot of luthiers on Instagram that swear by it. Hehe

[@OBrienGuitars]

If you build light enough then sure, you can opt to not scallop your braces. Most people over build so that is why they remove material from their braces.

[@thespiritof76..]

👍🏻

[@sirgreggins8824]

anyone know of a good place to buy quartersawn lumber to make bracing from?

[@rockymtnmovies]

RC Tonewoods

[@theleastcreative]

What kind of wood do you use to brace the top?

[@OBrienGuitars]

I use spruce.

[@eemacedo]

Robert. Você poderia me diz qual o "radius" do tampo e do fundo para violão aço da Martin?

[@OBrienGuitars]

Do Martin eu não sei mas eu uso 30 pés para o tampo e 15 pés para o fundo.

[@eemacedo]

@@OBrienGuitars Com 30 pés o som não fica muito agudo, ou não faz diferença. Eu estava pensando em usar 80 pés para o tampo. Estou muito errado?

[@OBrienGuitars]

@@eemacedo Tem varias maneiras de controlar a rigidez do tampo. O raio é so uma delas.

[@eemacedo]

@@OBrienGuitars ok obrigado. Sabe me dizer qual a medida do abaulamento para o raio de 30 pés?

[@EnemyBikeCo]

What happens if you don't radius the braces?

[@VictorMatsunaga]

Take this answer with lots of salt, since I don't know the math behind it. The top works as a "sounds membrane" in the sense that it needs to move across and along the grain in order to pump air from the sound hole. Much like how a speaker works. Therefore, the lighter and thinner it's built, the more potential it has. There's also the fact that steel string guitars, naturally produce a middle/ treble frequency, so you need to build a guitar that kind of high light the bass (for steelstring guitars, nylon strings is the other way around, you need to high light the highs and mids). A guitar isn't a magical instrument where you can add up infinite energy and it'll keep responding accordingly. As any (arguably everything) in the universe, there's a roof, a place in which one cannot go beyond. So are the Guitars. Guitars in general work with a fixed amount of energy, usually given by the tension of the strings. Therefore, a lighter top would be able to use this energy more efficiently than a heavier one, since there'd be less energy dissipation caused by friction , heat and top material resistance. Lastly, the guitar needs to be on the verge of breaking (meaning it needs to support the torque from the strings without collapsing), which means they need to have a structure capable of withstanding the tension on the top without warping, breaking or cracking. Ok after all these considerations, onto your 2 years old question: From what I said above, a guitar needs to be built as lightly as possible in order to be an efficient instrument. One way to add integrity to the top without adding lots of mass to it is giving it a radius (just like it's shown in the video). A top without radius would be more prone to bend if thinned as much as a top that'd be given a radius. the radius, of course, will add stiffness to the top, proving to high light high and mids, however, adding a radius to your top would enable you to make a lighter membrane to work with the fixed energy (strings), thus, proving to bring more efficiency for the whole system. DISCLAIMER: THESE THINGS I SAID ARE NOT ABSOLUTE TRUTHS AND I'M NOTHING MORE THAN AN AMATEUR BUILDER, IF THERE'S ANY INFORMATION WRONGFULLY GIVEN, I'M SORRY AND ACCEPTING YOUR KNOWLEDGE ON THE MATTER!

[@docscantlin]

Another reason for radius or arching the top is to resist cracking if the humidity dries it out. Also a curved top is stronger, hence you can brace lighter. Please correct me if necessary... This was a good response. Thanks.

[@Frankt117]

Excellent videos. If you set up a youtube page (or whatever its called) I'll subscribe

[@OBrienGuitars]

@sirgreggins8824 lmii dot com

[@markeharris3893]

Low volume level....

[@FreddysFrets]

That's why you have a volume control ;)

[@ivan868]

Very poor sound from bad microphone