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I have a line on a Caswell 10 inch buffer. If it’s the one I think it is (waiting to hear from the seller) it’s lowest speed is 900 rpm. Is this still too high? I see that 715 is recommended
Thanks, Craig

I use a shop fox arbor with a 12 and 16 in buffing wheel
a 1725 rpm 1/4 hp motor is all you need.

Cotten flannel and domet wheels

_________________
John Hall
blues creek guitars
Authorized CF Martin Repair
Co President of ASIA
You Don't know what you don't know until you know it

I use General Finishes High Performance Polyurethane and use 1100 rpm on a 10” wheel.


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Formerly know as Mandodiddle.

I find this subject very confusing...or at least mysterious

OK, so you've got a motor that has an rpm rating...fine...it's pulley interacts with another pulley on let's say the shop fox system...it would appear as if that pulley is larger than a motor pulley, so that steps down the rpm on the actual buffing wheels...then you've got the math behind the actual velocity of the buffing wheels...a larger diameter wheel is going to have more velocity than a smaller one, or put another way more of the buffing wheel is going to pass over the guitar per unit of time.

so it seems to me making simple statements about rpms doesn't say much actually...horsepower would certainly be important as that defines how much you can bog down the motor (e.g. press the guitar harder against the wheel)

from what I know of buffing using the type used on autos it's actually a pretty tricky proposition to get the perfect results, and what may really matter is becoming intimate with a specific system to know its in and outs and limits

just my 2 pennies

What John said, though my RPMs are a bit lower. What matters is torque. Too much, and ur guitar could end up in a pile of splinters on the floor. 1/4-1/3 hp max. I think my rpm is around 1000-1200. You should easily be able to stall the buffer with excess force. (Belt driven).

I use a grisly arbor (fox) with a 1/3 hp motor. 3 14” canton flannel wheels on both sides. Normally, I have to physically hand spin it to get it going. I like that.

I have been running my shop built arbor at approximately 700rpm for years and despite it being “recommended” by some I feel like it’s actually kinda slow. Thinking of swapping out pulleys to speed it up a bit.

I use a 1hp motor but a loose belt and can stall the wheels when I lean in.

Also, thinking of trying something more aggressive than flannel for the wheels too.


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What you should be looking at is the speed at the surface of your buffing wheel. And can depend on your finish too.....
SM buffer details -

A smaller wheel would need a higher RPM.
For the same speed with a 10" wheel as the SM buffer (14" wheel), the target speed is in inverse proportion to the diameter, this calculates -
14/10 x 715 = 1,001 RPM
So I would say 900 RPM on your 10" wheel is a safe speed to try to see for "your" finish, certainly for nitro.
If it's a tougher finish and/or buffing seems very slow, you should try a 12" wheel, which is 20% faster at the surface, would be better for heat dissipation and also clearance from the motor itself (shaft extenders are also available) or you could (maybe) up your speed a bit as it sounds like it's the variable speed buffer.

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The name catgut is confusing. There are two explanations for the mix up.

Catgut is an abbreviation of the word cattle gut. Gut strings are made from sheep or goat intestines, in the past even from horse, mule or donkey intestines.

Otherwise it could be from the word kitgut or kitstring. Kit meant fiddle, not kitten.

Colin is 100% correct its inch per min that is more important the rpm.
also the stiffness of the buffing wheel
so I use 2
cotten flannel and domet
also the compound cakes I use 4 from menzerna
polishing compound
buffing compounds I use # 3 4 and ultra finish 175
however as good as the wheels are a buffing pad is also important
I use a dual action buffer with 4 in pads
I also use buffing and polish compound
so it take a lot of learning to get that perfect finish.

No buffer can compensate for poor prep work so be sure
on a gloss finish
A seal
B fill
C seal
D finish application
E Process
F Technique

so here is my finish schedule
Seal I use recommended sealers by the manufacture Often Vinyl or shellac ( unwaxed flakes mixed in ever clear )
Filler most often I use aqua coat 3 applications
Sealer
I am a nitro guy so
4 to 6 coats 1 to 2 hour apart I keep my spray booth at 80 degree or higher there is
a dehumidifier in the booth to maintain RH and air flow

I use tape on the fretboard extension to measure build coats I want over .008 under .012

the dehumdifier allows level sanding in about 4 to 5 days
you will know if your ready as the sand paper wont pill I use klingspore and assilex papers
NOTE not all sand paper is the same you want a sand paper that is designed for finish work

when leveling here is the part that was hard to fathom use 400 grit
yes 400 grit
you are doing finish in 2 parts build coats then finish coat
so level sand with the 400 when done drop fill and touch up any weak point such as sinks or sand through

now 3 coats of final finish this I will thin about 20% using a mix 75% thinner 25% retarder if the RH is low I may use less
retarder heated to about 90 degrees

Apply a good wet coat on the first coat again rest 2 hr between coats

after 10 days level sand start with 1000 1200 1500 2000 then hand sand with assilex
then buff again if you need to do drop fills do this after 2000 and drop fill
I will then apply a coat on top of the drop fill this often cures up in a few days
once leveled you can start buffing and polishing.

I spend about 4 hr on final sand and buffing..

here is a tip
on my sanding I use a festool sander at slowest setting use the sander like a trowel keep the
weight at the training edge so you are leading on to the finish this helps the dust to clear and helps
avoid swirls

_________________
John Hall
blues creek guitars
Authorized CF Martin Repair
Co President of ASIA
You Don't know what you don't know until you know it

Great tips and schedule John, thanks.

Are the sandpaper grades you mention P or CAMI?

P It is also no hole I found that holes are gong to add to the swirl factor
it can be used dry or wet
I prefer dry on the initial level sand wet on final

_________________
John Hall
blues creek guitars
Authorized CF Martin Repair
Co President of ASIA
You Don't know what you don't know until you know it

Regarding the caswell buffer, make sure to check the arbor diameter. I had one for a while and the arbor was 3/4” so I couldn’t use the wheels from SM, Jescar, etc..


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Yes you can use those making an arbor shim is easy

I get my wheels from Grizzly Jescar and creswell

Making an arbor shim is as easy as wrapping it with solder or tape.

_________________
John Hall
blues creek guitars
Authorized CF Martin Repair
Co President of ASIA
You Don't know what you don't know until you know it

I would not have guessed that wrapping tape would work. Good to know.

Either way I’m much happier now with the SM setup.


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