Clever man.

When is that glitterball guitar going to be ready for a final buffing Boo? Feel another product test coming on?

As usual all the pics are in reverse order but I have never found a way to alter this other than manually retyping the file name in the post. Any hints on this much appreciated.

@darrenking Looks amazing Darren, nothing else to say at this point but well done. I do like the fact that it is speed variable. I have never used a guitar buffing machine before but have always wanted one. I don’t know what compounds to use on the 2K paint I use, I usually use Farecla products designed for wet buffing 2K. Can you buff 2K with a dry compound without burning through easily? I don’t know but I’m sure between us we can find out. I definitely wouldn’t want to try and wet polish with it. 🤣

The Glitterball will be ready for polishing in a couple of weeks or so, I’ve got a lot of painting and sanding to do before then. I would be happy do some test polishing on other guitars if you want me to give it a trial run. I definitely need to find the correct compounds, the ones sold at StewMac (other suppliers are available) are for polishing lacquers ie. Nitro. Does that stuff work on 2K auto paints? I’m all for trying nitro as a finishing product, it’s something I’ll have to learn and it’s another string to my painting bow. 

So I don’t really have anything to add apart from to say well done, you’ve done it again, a great affordable product for the guitar making community. 

PS. I just thought I would mention that we need to find the correct compounds to use for 2K paints. Did I mention that already? 🤘😝🤘

Thanks TV, much appreciated.

Darren

Hey Boo,

I’m pretty sure the techies at the polishingshop.co.uk will have some good advice on both the compounds and the best grade of mop to use for any given lacquer. I am happy to ask them the question unless you want to? I suspect that there may be more than one solution to achieving a really shiny finish but I think with guitars it is likely to be about keeping the temperature down. Automotive finishes are mostly on metal, which has a significantly higher capacity for soaking up heat than wood, so I’m guessing the compounds for guitars may be less aggressive. Could be wrong, won’t be the first time!

Cheers

Darren

The Glitterball will be ready for polishing in a couple of weeks or so, I’ve got a lot of painting and sanding to do before then. I would be happy do some test polishing on other guitars if you want me to give it a trial run.

Great - thats going to be interesting to see.

👍

I’m pretty sure the techies at the polishingshop.co.uk will have some good advice on both the compounds and the best grade of mop to use for any given lacquer. I am happy to ask them the question unless you want to? I suspect that there may be more than one solution to achieving a really shiny finish but I think with guitars it is likely to be about keeping the temperature down. Automotive finishes are mostly on metal, which has a significantly higher capacity for soaking up heat than wood, so I’m guessing the compounds for guitars may be less aggressive. Could be wrong, won’t be the first time!

@darrenking Next time you are speaking to them, if you could ask them what products to use for 2K auto paints, that would be great Darren, thanks. 

I still haven’t got to the bottom of what exact clear coats other guitar makers use, other than Nitro. People say poly but that is such a generic term. Nobody ever gives an example of a product name, a manufacturer, a brand. That’s why I either do oil finishes or use the auto 2K system that I know and love if I want a full on shiny shiny guitar. 

Using an auto polishing system such as Farecla (many others exist), uses liquid compounds and water to keep the temperature down to prevent burning through the paint. It’s also the same as any polishing system though in that you need friction but not too much. So it is your friend but also your enemy, you have to keep the balance right. The trick to achieving that is to keep moving, don’t spend too much time in one place or you will burn though. I think you are right though that the non auto compounds will be less aggressive but I think the mops will make a difference also. 

Polishing is a whole world in itself, it’s obviously connected to painting and painters can talk endlessly about different products but polishing is just as important to achieving a fantastic finish than the paint and it’s application. I wish it was as simple as buying some “guitar paint” and “guitar polish” but it’s not. 🤯

Hi Boo,

This is the standard information that they publish covering car polishing systems and those suggested for guitar polishing. I’ll give them a ring next week and ask the question though.

Darren

https://www.thepolishingshop.co.uk/guide-to-menzerna-compounds-for-woods-plastics-and-lacquer

https://www.thepolishingshop.co.uk/menzerna-carpolishing-guides

Hi Darren.

Fantastic idea and a great alternative to the SM buffer for people with limited space and the predicted budget certainly makes it affordable.

Have you thought about any "give" in the speed of it. The SM one and most of the home made buffers I've seen have a belt drive that you can slacken off to allow for belt slippage, so the mop slows down under too much pressure. Helping prevent burn through. Do you think this motor will do the same?

Another question would be the length of the shaft itself and how you attach the mops to it, either a screw with plates like SM or have you thought of another way. I have 14" SM mops and the 12" polishing shop ones. It was easier to get the bushes I had made fixed to the metal SM ones than the PShop type using M6 bolts. The Pshops are like a highly compressed cardboard centre piece with metal reinforcement discs. So you may have to thread the bar and use lock nuts which will give it extra weight at the end of the shaft. I presume it will be reliant on the motor drive shaft bearing and the pillow block one for stopping any flex in the main shaft under use.

(@boo) Darren is right the Polishing shop has loads of information on polishing compounds etc on its website. Well worth a read regarding Menzerna anyway.

👍

Hi Mike,

thanks for your comments. The shaft protrudes from the external bearing by about 300mm and at 25mm thick I don’t expect a lot of flex. The final 100mm is reduced to 20mm and the end is threaded M20 to accept a large Nyloc nut. The shaft has an 8mm through hole so you will only need one spanner and a length of steel rod to undo the nut. The polishing shop mops can be ordered with the centre hole bored out to a specified dimension and it shouldn’t be difficult to make adapter plates for the StewMac, or any other, type of mop. I’ll post a drawing of the shaft this afternoon.

With regards to slippage of the mop, this isn’t something that you should expect with this system as the mop shaft is directly connected to the servo shaft. If you are actually pressing so hard that you are stalling the motor I think there would be a danger that you overheat the servo. Having never used this type of guitar buffer before I am talking blind, so to speak, but I think that having the adjustable speed should be the first method of avoiding burn through. We’ll see when it actually get used in anger I suppose.

Cheers

Darren

This is the drawing of the shaft and it actually protrudes by about 335mm in front of the bearing which should give plenty of accessibility. Also, because the buffer doesn't have a support stand, it is possible to mount it in a variety of positions on the corner of a bench and to give excellent clearance below it.

@darrenking

That whole thing looks like a neat solution. I had been wondering how you were going to couple the polisher shaft to the motor shaft. Now that I've seen your drawing that is clear now. I'm assuming that the two grub screws locate in the motor shaft keyway. Are there also grub screws on the bearing block that grip the shaft?   I agree that there shouldn't be any significant deflection. I do have a small concern that there might be a bit of wobble that could cause vibration and wear at the grub screws. If that were to become a problem, can I suggest the addition of dimples in the shaft to locate the bearing grub screws, that would stop the shaft from creeping out if the grub screws did loose their grip.

Hi Darren.

When I was talking about slippage I meant in the context of an inbuilt "clutch" similar to Robbie O'Brien's (

) Hopefully you wont need it but if you press too hard it slows down, hence less burnout of the finish. As to the overall shaft length I've attached a pic of the one I built recently and your dimensions are 7-8cm shorter from centre to mop. The second pic shows that you have to take care whilst doing the edges of the body as its easy to catch it on the centre stand or box section on yours. Even if you are careful, I know it still happens 😥. Possibly angle the front end mount to allow a little more clearance.  

 I am just being over cautious here I know. Ask Mark I am always tentative about machines that can give you firewood quickly 😀 

I was going to say that I've used a polishing machine on a guitar, but that's not quite true.

I've seen one being used on the fretboard of a guitar that I'd made, but the guy using it declined to let me do the finishing myself.  He achieved a beautiful shiny finish to the ebony board but advised that I'd probably wreck it if I tried myself.  

At the time, that seemed a bit over cautious to me.  It's a polisher, not a sanding machine (OK, I guess it's effectively a very gentle sanding machine).  Can you do real damage to the article that's being finished, or - provided that you're not a complete numpty - is it a reasonably safe process?

Love the concept, and the fact that Darren has taken the time to design it, get it built, and would be offering it to us potential customer.

I'd worry that I'd need to practice a lot first, before actually using it on something that I wanted to keep, rather than put on a fire.

Am I worrying unnecessarily?

@tv101

Like anything else there’s a learning curve. I haven’t used a buffer personally but have seen it done and have read about them. The biggest danger aside from burn through is the buffing wheel (sorry but I can’t bring myself to call it a mop 😆) either throwing the workpiece at you, straight to the floor or across the shop. I can’t explain it properly but whatever you’re buffing needs to have the top edge held away from the wheel so it doesn’t catch, do you know what I mean?

Here our old friend Dan shows off his sweet ass buffer. He doesn’t talk about how not to do it but by watching you’ll see what I mean. Obviously youtube has lots of vids to explore on the subject but  Dan gives some good general tips here. 

@darrenking

Looks like you have covered all the bases with design and the need to store in a small space.

I've never used an electric machine for instrument polishing but have done a bit of metal polishing or linishing as its called including sterling silver when I was taking jewellery making classes pre Covid ( anyone still remember that). Also plastic polishing which just uses different compounds and mops. Plastic is very sensitive and would be good practice to learn how to develop a light touch. Old pick guards are good.

The basics shouldn't be too different, ie touching the workpiece lightly to the wheel and not holding it there for too long. Like everything else you have to know when to stop. If you don't start to get a shine fairly quickly then repeated polishing isn't going to make it any better. Finish is usually multiple layers so it's easy to polish through the top layer and leave a patch - the nightmare scenario even on clear coat.

Excuse me if I'm saying stuff that people already know. The different grades of mops start with hard/medium/soft felt used with a coarse compound for rough work. Then stitched cotton mops with medium compound. Then loose leaf mops with fine compound for finishing. Regular cleaning of mops is also important to prevent hard build up which can tear the finish. 

@tv101

Yes it's possible to ruin a workpiece with over zealous polishing. Guess how I know.

Martin guitars polish the body and neck before they are joined together. I have a photo somewhere.

Just to depress everyone this is how big factories do polishing, no people input. The arm uses suction and is computer controlled. Probably even a machine for loading and removing the bodies in and out of the room.

Just to depress everyone this is how big factories do polishing, no people input. The arm uses suction and is computer controlled. Probably even a machine for loading and removing the bodies in and out of the room.

@rocknroller “I think we’re gonna need a bigger boat.” 

I think we should just pool all our resources and skills, form a guitar company and buy a factory to put all our gear in. 🤣 Do you think we would make any money? 

@boo

I was reading your earlier comment about poly finishes on guitars and did some web research as it's something I've often wondered myself. It's seems that big firms used a two pack system which you would be OK with being a trained sprayer but not something for the amateur. Probably something that isn't available in this country or Europe any more after the changes to VOC regulations in 2007.

Heres a link to how Fender used different finishes which mentions poly.

https://www.fender.com/articles/tech-talk/the-science-and-style-of-finishes//