Luthier Tips du Jour - Closing The Box

Luthier and Instructor, Robert O'Brien, shows several ways to attach a guitar back or top to the sides.

[@fr0ilan]

I love watching all your luthier tips videos. I ended up using saran wrap to close my box because I didn't have access to any of your preferred methods. It worked pretty well!

[@jasonadams527]

You could have also used cord and wedges by wrapping with the cord as tightly as possible like the rubber bands then snugging up with wedges on the bottom side. There are a million and one ways to do these kind of things and the saran wrap or shrink wrap is very creative! Thinking outside the box... But the clamp method is my favorite which goes to prove the old woodworkers adage, you can never have too many clamps.

[@OBrienGuitars]

@biggestclaptonfan The tapering of the sides is usually done on the back. I use a 30 foot radius on the top of my sides with no taper other than the radius itself and have never had a problem with neck setting.

[@mirkovukoja233]

:D Boys are natural! Great work sir

[@sirgreggins8824]

quick tip if you're buying pre-radiused braces. Take your template and trace it onto a piece of card board. Take some 1/8" thick cork and glue it to the rim of the cardboard template. This will allow the soundboard or the back to dip in the middle and will conform to the radii of the bracing. This of course is only if youre using pre radiused bracing like from stewmac or wherever

[@OBrienGuitars]

Soundports are a fairly complicated issue to describe here. Basically it allows an extra port for the air to leave the instrument and thus frees up the top and back plates to move more freely.

[@paulypisspants7340]

tractor tires still use inner tubes

[@Mrmatthewjpowell]

thanks so much for the quick response!

[@OBrienGuitars]

@TomDodsonMusic Buy two dishes. I use 10 for the back and 30 for the top of my acoustic guitars. Glad you are enjoying the videos.

[@OBrienGuitars]

@wackmac The traditional Spanish makers radius the backs but not in dishes. I use a more modern approach and radius my classical backs to a 15 foot radius using a dish

[@OBrienGuitars]

I put my back braces, X brace and upper transverse brace through the kerfing. Some people do it other ways. Find a way that works best for you and the sound you are trying to achieve.

[@behradgorgani]

Hi Robret, Love your videos, quick question, what do you think of the spanish heel design for a steel string acoustic? I know it will be hard to do any neck reset down the road but I've seen some pro builders use it. I just wanted to know if its worth a shot? thanks again

[@OBrienGuitars]

@jonnburton Eliminate the high spots first to get the radius close and then true it up in a radius dish.

[@EthanSh1n]

What kind of block plane would you recommend to plane the sides flush?

[@sirgreggins8824]

@TomDodsonMusic some ppl use 20 for the top and 28 for the back. personal preferences

[@torusama1959]

Dear Robert, I have LMII two radius dishes and I would like to rotate them when sand both sides (Top and Back of a guitar). I made a hole on the center of dishes and set up a pillar. It works very well, I guess. Well, I am just wondering where the center of Top and Back are. In case of X-bracing, I guess the crossing point of X-bracing is the center of Top and Back. How do you recommend where the center of Top and Back of a guitar? Thank you.

[@OBrienGuitars]

I don't think it matters where you position the sides in the dish. You will be close enough to the actual center.

[@torusama1959]

It means the center of the body length is the center, right?

[@EthanSh1n]

I would obviously like to find the most inexpensive option for a plane, but I am well aware buying quality tools are a must. To tell you the truth I'm not really sure what price range good hand planes go for haha

[@jonnburton]

Hi Robbie - just a question about radiusing the back... If you have a taper from the waist area to the headblock, how do you go about doing the radiusing? Do you eliminate the high spots with the plane, thus making the taper less pronounced, or would you rock the assembly (with the waist area as the pivot), alternately sanding the headblock and lower bouts on the dish..?

[@farrukh1994]

why there is a hole or a sound port in upper waist??i heard somewhere it projects the sound.if a close box has a whole somewhere else in the side,then the sound gonna be leaked.does it effects the sound.i saw some classical guitar having a two holes in front near to neck heel.

[@biggestclaptonfan]

Hi there, I was just wondering what your opinion is on tapering the sides, on the tops side, down by 1.5 digrees to accomadate the neck set? or does radiusing in a 28' dish accomodate for this? Thanks Paul

[@Mrmatthewjpowell]

When using the discs to radius the sides (topside) do you avoid the head block to keep the corner that accommodates the neck square? or do you spin the complete edge of the sides and both blocks in the dish? in the closing the box video it looks like you hold a square to that corner.

[@OBrienGuitars]

+Matthew Powell The top and back rims get a complete radius, including the blocks. The neck is not attached at 90 degrees.

[@farrukh1994]

why it is necessary to cross the brace through kerfing.it is for rigidity or sound quality?do these braces work as sound bus?i mean taking vibrations from top to back and sides?

[@johnsweda2999]

When using the rubber bands be better to put a piece of two by two down the centre so the clamping pressure is on the centre of the guitar less likely to split the sides of the wood as well I can't hear your recordings way too low... I have it on maximum volume is there any chance you could redo them at higher volume output.

[@allnsntll]

you can buy pond rubber and cut your own. I used to build water features. There I saved you some money, now build me a free flat top! :)

[@juliantaylor7663]

when you close your box do you glue the top & back separately or both in one go?

[@OBrienGuitars]

I used to to do it all in one go. These days I put the back on first and then clean out the glue squeeze out before installing the top.

[@juliantaylor7663]

When you were removing the kerfing can you use a chisel instead of a router?

[@OBrienGuitars]

sure, a chisel or file will work fine for this.

[@OBrienGuitars]

How much money do you want to spend?

[@OBrienGuitars]

I think there are better alternatives to the Spanish heel design on a steel string guitar

[@sirgreggins8824]

i like to use 100 ft of rope. I clamp the guitar at the blocks and then use a slip knot and close it up. Never a single gap.

[@LeddingtonGuitars]

Micro-Scosche... a new unit.

[@mtmals9786]

I used twill tape and one edge of the back cracked just at the edge of the side. My first build is okay so far..the excess flush routed nicely. Binding channel is next. Slide show see flamenco build at taowriter5000.com. Thanks for the fine lessons Robbie.

[@jasonadams527]

In my opinion and that is all it is. You don't need to use that much pressure, just enough to close the gap if your fitment is good and as Robert said, it pays to trim the top or back to at least a 1/4" or less of flush then the leverage is not so much to crack it. I used to over clamp things and still do sometimes so your not alone.