How to make an Acoustic Guitar Mold | Building an Acoustic Guitar

I never saw a mold being built before. I’m impressed. You are a true craftsman.

You're a life saver!! Love your video, perfectly explained!!

Looks awesome to me, and the spreader idea was awesome. gonna come back to this when I make my own mold.

man I've been watching and learning from your channel since you started it! Truly inspirational dude thanks for passing on the knowledge

Love your videos mate. You have a great way of describing your processes. Thanks for posting them

You're one step ahead of me!!! Just wrapped up my frame today... Spreaders are next.

Floating block is a great idea. In fact it’s the best way

Absolutely awesome and inspiring, thank you thank you !!!!!

You are a true master mate. This is a very helpful video as i’m trying to build an acoustic guitar myself. Thank you and compliments.

Great information! Thanks!

Awesome video!

Awesome! Looking forward to more!

Another fantastic and informative episode.

This is a fantastic informative video, great job Jeff👊🏼🥃🇺🇸

Over 20 years both acoustic build and repair work... believe me - those spreaders really need to fit through the sound hole if shape is to be maintained through the plates going on the rim. For those that are not getting accurate or stable bends on their sides, you really want to work on tweaking your process. - either pipe or blanket bender - to get close enough that a single waist spreader gets the side in close contact along the entire mold. For those that have some issues there, a small upper and lower bout spreader will usually pull things back into alignment, but try to go into the profiling, side tape, and lining process with as accurate a set of sides as possible. On MDF - heavy, not very stiff, and will need some protection from water. 18mm Hardwood plywood - even the poplar-core stuff from Home Depot - is nicer to work with and about 75% of the weight of MDF, and only about $20 more a sheet (a mold with spreaders and . To get the same stiffness in the mold through the waist, MDF needs to be 3" wide, versus about 2-3/8" for plywood, as stiffness is about 50 percent of hardwood ply in-plane . Again, MDF is about 65 lb/cu ft versus about 38-40 lbs/cu ft for hardwood ply, so plywood molds weigh about half of what an MDF mold will weigh for the same stiffness (which is why you want a mold to begin with). You want to be able to easily hang the mold off a luthier's swivel-jaw reaper vise for linings, etc, so weight matters. You also want to be able to hand a mold which is in use off the floor and out of harm's way until the closed box is ready to come ou too the mold. A 5/8" hanger hole centered about 1-1/4" up from the inside edge of the upper bout profile and on the seam between halves of the mold keeps things out of the way of the carriage bolt/wing nut closure, and a modified screw-in ladder hanger bracket (heat the bent-up tip and bend such that there is just enough upward kick to keep the mold on the hander). Titebond is a good utility glue for this work - horrible for actual instrument construction (it hot and cold creeps, is challenging to regale without full removal, and has such poor initial tack that you'll have to either use alignment pins or clamp twice - ounce to get most of the excess glue squeezed out, and then again for alignment).

Cool idea with the floating blocks. If I was to build an acoustic guitar, that would be what I would do. However, I would have cut the hole for the turnbuckles out of the middle piece of MDF then drilling the outer ones before gluing together to save time later, but that's just me. Yours looks like they will do the job perfectly!!

Excellent video

Nice Video! You might want to consider making the blocks small enough yo remove thru the sound hope. That way you can leave them in during the entire glue up of the body. Also the finish of the block , inside the form, should include the thickness of the sides as that will slightly change your radius.

Gunk.... definitely a technical term!

I just finished one of these. I only used one set of spreaders though and placed them at the waist(narrow part) of the mold. I used 5/8" oak dowels through the spreader hardware. There should not need to be that much pressure on the sides. I used leather too.