Build Thread - McKnight Mini Mac (SJ) !

[PhilipY]

This time Tim shared the process of pore-filling. Lets go into details.

After finals sanding on the body and neck it’s time to spray sealer on the body and neck:




24 hours later, after the sealer has dried thoroughly, begins the pore filling process. All “open grained” wood has visible and microscopic open pores that must be filled, prior to finish application, to ensure the final finish will be completely level. The pores can vary in size depending on the species of the wood. If the pores are left unfilled then they will show as voids under the finish and look horrible.



A squeegee is used to force the filler resin into the pores while removing any excess build up on the surface of the wood.


It only takes a few grams of the material to fill all of the pores.



Only the back and sides will require pore filling. The redwood top is classified as a “Closed pore” wood.

[PhilipY]

After the pore filler has cured for 48 hours, any excess material is sanded off the wood. This leaves the wood’s surface completely flat and ready to continue the finish process. Here Tim is spraying a second coat of catalyzed urethane lacquer sealer over the pore filler.

[PhilipY]

Thanks to Tim and Mary, now I got a little knowledge about sanding:

The 3 & 4 coats of initial coats of finish are sanded flat which makes the finished surfaces look frosted.



The sanding step insures all of the pores are sanded level and allows the final coats of finish to lay completely flat on the surface.



After the body and neck are sanded it’s time to remove all of the sanding dust and prepare for the final coats of finish:



First coat of the final 3 & 4 going on. Back, sides and neck get 4 final coats and the top gets only 3 coats:



The fresh finish over the top of the frosty sanded surfaces makes it look completely shiny again and removes all of the frosty appearance of the previous coats of finish:

[PhilipY]

Here are more updates from Tim...
It looks almost finished and Tim confirmed that there are just a couple of weeks left.
Btw, due to the limit of uploading images, I will make several posts.

Dry sanding body and neck with 600 grit sand paper then 800 grit sand paper prior to buffing:




Next we wet sand all flat surfaces using an air powered sander using 1000, 1200, 1500 and 2000 grit sand papers. The mixture of water and Murphy’s Oil Soap keeps the surface lubricated and prevents the sand paper from loading up with fine finish particles.





The binding edges have to be hand sanded using the same sanding schedule as above. Sanding is a boring yet complicated task and unfortunately there are no short cuts if we want to end up with a perfectly flat mirror like glossy finish in the end. After sanding with 600 grit sandpaper, 600 grit scratches are left behind on the surface. Next we sand with 800 grit sandpaper to remove the 600 grit scratches in the finish but this of course leaves 800 grit scratches in the finish. If we started buffing the finish now then the 800 grit scratches would show through in the finish reflections. We have to sand progressively through each grit all the way to 2000 grit and only then can we begin the progressive buffing process.

[PhilipY]

After sanding then we begin buffing using coarse buffing compound to remove the 2000 grit sanding scratches.



After the body and neck are buffed with 4 courses of buffing compounds (Coarse, Medium, Fine and Very Fine) then it’s time to remove the masking tape from the fingerboard face:




Then glue the neck to the body:



While the glue dries on the neck it’s time to make the bridge:



Drill and counter sink the bridge pin holes:



Progressively sand the bridge from 220 through 1500 sandpaper grits:

[PhilipY]

Sand the bridge’s gluing surface on a sand paper covered granite plate:




Scribe cut through the finish using a SHARP surgical scalpel:



Peel off the .001” thick Frisket masking film from the bridge gluing surface area:




Then Tim measures the .001” thick Frisket film and finish which measures .003” which means the finish itself is only .002” thick.



To put the finish thickness into context a sheep of computer printer paper is .005” thick which means the finish film thickness is less than ½ the thickness of a sheet of paper.


Tim makes these small Teflon pins to insert into the E and e bridge pin holes:

[PhilipY]

These pins are to locate the bridge and hold its position while the Hot Hide Glue dries:



Tim applies Hot Hide Glue to the bottom of the bridge and also to the top:







He holds the bridge in place while wiping off the HHG squeeze out using hot water and a rag:



Then a vacuum clamp is used to apply even clamping pressure to the bridge while the HHG Sets:

[Nemoman]

This is really looking good--that cocobolo is awesome.

Really getting close now!

[Neil K Walk]

Thanks for sharing the details regarding the finish sanding. I need to write that down and follow it to the letter because that finish came out looking really nice!

[Tim McKnight]

Originally Posted by Nemoman

This is really looking good--that cocobolo is awesome.

Really getting close now!

It is getting close to completion but we still have a lot of work ahead, Thanks for following along Nemoman.

Originally Posted by Neil K Walk

Thanks for sharing the details regarding the finish sanding. I need to write that down and follow it to the letter because that finish came out looking really nice!

Unfortunately there are no shortcuts Neil. Believe me, I've tried. My dad was a master cabinet maker and I just hated it when he taught me how to sand "through the courses". Its a tried and proven procedure that works but its certainly not fun doing it. However, the end results speak for them selves and are part of what separates the men from the boys.

[Crosswind]

Wow, that is a really thin finish! And it's looking great!

[Neil K Walk]

Originally Posted by Tim McKnight

Unfortunately there are no shortcuts Neil. Believe me, I've tried. My dad was a master cabinet maker and I just hated it when he taught me how to sand "through the courses". Its a tried and proven procedure that works but its certainly not fun doing it. However, the end results speak for them selves and are part of what separates the men from the boys.

I guess I need to start wearing long pants in the shop then lol!

[Eire]

Originally Posted by Neil K Walk

I guess I need to start wearing long pants in the shop then lol!

Naw, Neil. You've always looked just fine decked out in your onesie.

This build is like watching Tim create my "Petoskey" fifteen years ago. All but identically the same woods across the board, same model and cutaway, with but an inner ring in my rosette being the notable difference. It should also sound like my McKnight, which will make Phillip an extremely delighted McKnight guitar owner in a lengthy line of extremely delighted McKnight guitar owners.

[PhilipY]

The day is getting closer and closer.

Tim has installed the fingerguard and strung up the guitar:

Making a clear pick guard:




It’s in place now:



Clear protective film can be pulled off the top of the clear pick guard if the outer one becomes scratched with pick marks or nails:




Laying out the string spacings on the nut:




Neck block label:



And soundhole label:

[PhilipY]

Further more from Tim:


Beveled end of the pin goes against the string ball. Use the pin to push the ball into the hole, while holding upward tension on the string. When the ball is through the hole it will slip off the ball and into place:




There is a .020” thick shim under the saddle now to provide slightly higher action for a more aggressive string attack. The shim can be removed to lower the action for delicate finger style playing:



With the shim in place the action at the 12th fret measures .080” at the bass E and .050” at the treble e string.



The guitar will now go through a 72 hour ToneRite treatment to allow all the pieces and parts to settle in. Then Tim will do the final set up tweaks and then it will be time to box it up and ship it off to its new home: