Official Luthiers Forum!

I just got the buffing machine from lmii along with their buffing wheels and compound. I also got a 1/3hp 1725rpm motor. That's what lmii had recommended on thier website but now I've been reading some more information and its making me think that is to fast. Im using a 2k urethane finish. So how does that compare to laqure. I have never buffed before so ill take any other advice also.

I have the buffing machine from Caswell Plating. It has a 3/4 HP, 1100 RPM motor. Stew-Mac's has a 3/4 HP motor that runs at 1725 RPM; the pulley in their arbor must slow it down to the 715 RPM they list. I'm interested to see what others who have a better understanding of gearing and what not have to say.

One of the things I appreciate about mine is that I can slow the buffs down with pressure, meaning the motor isn't too powerful. You want less power than more here. It sounds like you got the motor LMI recommends, so I'd feel confident with it.

A buddy of mine used an old washing machine motor, and used a belt with different sized pulleys to slow down the buffer. Worked great.

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"Act your age, not your shoe size" - Prince

I used a buffing wheel on my lathe for bowls and found it difficult to control much over 700-1000 rpms. That's a 1 hp motor. I'm thinking about how I'm going to use it on my guitars, first two are approaching finishing stage. It grabs stuff and flings it if you get too close. So low speed and careful. 1/2 hp motor is the minimum I see recommended for direct drive, but I would gear it down to 500 or so.

They do a great job.

It's about surface speed of the buffs so buff diameter is a factor too. you want a buff surface speed of 2500-2700 feet per minute. from there it is gear reduction to pick the right pulleys.

I think a 1/2 horse motor is a bit light. 3/4 works well and anything over 1hp would be overkill.

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Brian

You never know what you are capable of until you actually try.

https://www.howardguitarsdelaware.com/

I have a 1/3 hp with a shop fox arbor and 12" wheels. Has enough power but will bog down if I push hard which is good. I've buffed nitro, ktm-9 and shellac.

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Pat

First one I used was 15 yrs ago, in a class; it was mounted on a drill press. Speed was slow and it worked great.

Half a horse here, run a slack belt., geared for same surface speed as SM buffer but using 12" wheels.
Using enduro-var.

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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.

Usually, by this time, someone chimes in with the concern about excess HP grabbing the guitar and turning into kindling. I use 1/3 HP with two caswell canton cotton buffs on each side (14"), geared down to ~800 rpm. Even at this low HP, it can scare me at times. But I can stall it too. Safely. And I've never burnt any finish. Now, I would agree for hard finishes (polyester), this would not be sufficient. But for waterborne, nitro, etc, its fine.

Brian, do you keep your belt loose?

I use the exact same buffs , compounds ,speed, etc. for all types of finishes. Polyester, lacquer, urethanes, varnish and even french polish. The key is learning how much pressure and how fast to move the surface over the buff for each type.That is where the difference in coating type comes in.

The reason buffers grab and throw guitars is bad technique or inattention to the work. My first rule to help prevent this is I always wear a pair of work gloves. I like the "Field Grip" brand from Home Depot or something similar. As the surface gets glossy it gets slippery. Gloves help be hang onto it and prevent any fingernail dents. They also allow me to use my hand a s a shield when buffing tight cutaways and such. Concentration and a firm grip are key. It is easy to let your grip lighten up when you are using the finer compounds and really flying across the surface . This is when disaster usually strikes.

I run a link belt for reduced vibration and keep it very snug for the same reason. Vibrations and/or changes in speed (such as bogging or stalling the buffs) have very negative effects on surface quality. Stalling a buff while buffing can leave deep marks in the finish that will require maybe even re-sanding to remove depending on the type of finish and how cured it is. If the buff slows down even a 100 rpm it can start to lose it's cut efficiency and require longer time on the buff and generally build more heat in the coating which is a bad thing...... Buff speed and it's consistency cannot be stressed enough if you want to achive quality results in a reasonable time for this type set up.

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Brian

You never know what you are capable of until you actually try.

https://www.howardguitarsdelaware.com/

Well Brian, that's why I asked. I'm always open to learning and improving. I followed the low hp advice for years. But, I admit I sometimes wonder if I'm missing something. I think it was good for me to learn technique on a low hp device. But I think I'm ready to graduate. Does this make sense? I'm going to search out a similar motor at higher hp. And link belt. I'll probably widen to 3 buffs on a side. Motor recommendation appreciated.

I also find that wider buffing heads can be a problem. they will not get into the waist of the body very well and can in fact give "edge burn" if they are much to wide for the inside contour. I have come to prefer narrower buffs as stripping down to get cutaways etc is a bummer.

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Brian

You never know what you are capable of until you actually try.

https://www.howardguitarsdelaware.com/