Polishing Epoxy with a Rotex

[TomInNC]

I'm almost at the finishing part of the waterfall table guild build, and I am considering polishing the epoxy portion of the table up to a high gloss. Has anyone polished epoxy with a Rotex? If so, what pad and compounds did you use? 

[Chestnut]

Depends on the end sheen you are looking for. I sand through the grits 120-180-220-320-400. I usually stop there and apply finish over epoxy and it looks the way I want it. To take it further I'd use 1,000 and then 2,000 festool Platin pads. These pads aren't designed for use with the rotex though and in my experience perform best when lubricated with a mineral oil / mineral spirits mixture.

Polishing epoxy near bare wood can be very difficult I'd be interested in some opinions on how this is accomplished if the wood isn't finished prior to polishing. I don't have the guild build but feel like Cremona should have covered this? Well i guess he uses ARS for everything so maybe isn't covered to hardwax oil standards? I suppose I should ask what finish you intend to use.

 I've also polished wood and epoxy with stropping compound. Worked superb. The walnut burl took a mirror polish and didn't even need finish.

[fcschoenthal]

Blacktail Studios has THIS video showing the results on sanding a slab (with epoxy) up to 12,000 grit.

I think he uses an ETS sander instead of the Rotex, but there are buffing pads for the RO sanders that would probably work. I haven't tried them on mine.

[Tom King]

If I'm polishing anything, I use one of a couple of different sizes of polishers, foam pads, and automotive machine polishing compound.   3M Perfect It is one I've used for several decades.  A little bit goes a long ways, and a quart lasts what seems like forever.

I've never polished epoxy that I remember, but Many square feet of gelcoat which should work the same way.

https://www.3m.com/3M/en_US/collision-repair-us/featured-products/perfect-it/

[BonPacific]

I'll second 3M's Perfect It for epoxy polishing. I use it for dice.

[Tom King]

This is a great little polisher for small things, and even the front of a vehicle around the lights and such where a big one is more than a handful.

https://www.milwaukeetool.com/Products/Power-Tools/Metalworking/Sanders-and-Polishers/2438-22X

These cheap foam pads work fine on it.

https://www.amazon.com/RUISHU-Polishing-Attachment-Automotive-Accessories/dp/B099RNBV83/ref=sr_1_3_sspa?crid=3NUVBKRTLVAD3&keywords=polishing+foam+pad&qid=1664294523&qu=eyJxc2MiOiI0LjUzIiwicXNhIjoiNC4zNCIsInFzcCI6IjMuNjkifQ%3D%3D&sprefix=polishing+foam+pad%2Caps%2C96&sr=8-3-spons&psc=1&spLa=ZW5jcnlwdGVkUXVhbGlmaWVyPUFXUDgzWTY1TkdKQTUmZW5jcnlwdGVkSWQ9QTAwMDgzMTkyT1kwQlFJUDZBNlMyJmVuY3J5cHRlZEFkSWQ9QTA0MTczOTYyMDlPSDBIMjJDVkJWJndpZGdldE5hbWU9c3BfYXRmJmFjdGlvbj1jbGlja1JlZGlyZWN0JmRvTm90TG9nQ2xpY2s9dHJ1ZQ==

[TomInNC]

On 9/26/2022 at 11:14 AM, Chestnut said:

Depends on the end sheen you are looking for. I sand through the grits 120-180-220-320-400. I usually stop there and apply finish over epoxy and it looks the way I want it. To take it further I'd use 1,000 and then 2,000 festool Platin pads. These pads aren't designed for use with the rotex though and in my experience perform best when lubricated with a mineral oil / mineral spirits mixture.

Polishing epoxy near bare wood can be very difficult I'd be interested in some opinions on how this is accomplished if the wood isn't finished prior to polishing. I don't have the guild build but feel like Cremona should have covered this? Well i guess he uses ARS for everything so maybe isn't covered to hardwax oil standards? I suppose I should ask what finish you intend to use.

 I've also polished wood and epoxy with stropping compound. Worked superb. The walnut burl took a mirror polish and didn't even need finish.

I just went back and watched the guild video again, and Cremona just mentions using a Platin abrasive from Festool and mentions the possibility of using polishing compounds. I'm not sure what you meant by ARS above, but I plan on using Rubio monocoat. 

For my first crack at epoxy, I tried using the high grit Fusion Foam pads from Klingspor after sanding through 220 with regular discs. I'm not sure if I screwed something up, but I was getting small white flecks showing up in the epoxy, so I stopped using them. Note that this was on the epoxy portion of the table only and not on the wood, which I sanded to 180.

I see that the BlackTail video also shows using some kind of micro mesh high grit pad. In the videos, Cam seems to disconnect the dust collection at some point. Is this always recommended for these types of pads? At least in the case of the Fusion Foam, I could not see any holes in the pad itself, so it wasn't clear what, if anything, the vac would do for dust collection.

 

 

 

 

 

 

[Chestnut]

Micromesh high grit pad seems like a description for the festool platin pads. DC gets disconnected because there aren't any holes for the dust to go through so the vac isn't likely to do much.

Cremona finishes with ARS (Arm-R-Seal from general finishes) because he is finishing with a polyurethane some finishing steps that he doesn't take may need to be taken when using another finish. I don't know what would cause white flecks but 220 isn't likely to be a good finishing grit for epoxy, you'll need to go higher when finishing with rubio.

[Tom King]

The flecks may be bubbles that were cut open by the sanding.

[TomInNC]

On 9/28/2022 at 7:12 PM, Chestnut said:

Micromesh high grit pad seems like a description for the festool platin pads. DC gets disconnected because there aren't any holes for the dust to go through so the vac isn't likely to do much.

Cremona finishes with ARS (Arm-R-Seal from general finishes) because he is finishing with a polyurethane some finishing steps that he doesn't take may need to be taken when using another finish. I don't know what would cause white flecks but 220 isn't likely to be a good finishing grit for epoxy, you'll need to go higher when finishing with rubio.

Thanks for the clarification. Regarding the Rubio application, when I built my first epoxy-wood table, I asked them about the sanding progression, and they said to not take the wood beyond 180 because it would interfere with how the oil bonds with the wood. Rubio also indicated that you can take the epoxy to whatever grit you want because the oil effectively just lays on top of the epoxy instead of bonding with it. 

I should have added that on my previous river table, when I noticed the flecks developing while sanding the bottom of the table, I opted not to sand beyond 220 and instead used Micro Gloss liquid abrasive and a Vlies pad to rub it in. I think I effectively skipped several thousand grit in terms of the suggested grit sequence for using the Micro Gloss, but I had a hard deadline on finishing the project for someone, and the epoxy looked very good afterwards, albeit with less sheen than I was hoping for. Since I'm not under the gun of a deadline for this build, I was hoping to do things right this time. Haha. 

 

[TomInNC]

On 9/28/2022 at 7:44 PM, Tom King said:

The flecks may be bubbles that were cut open by the sanding.

Thanks. I didn't think about that. When you have tinted epoxy, is there a good way to address these types of imperfections? Since the flecks were on the underside of the table and they were hardly visible after applying the finish, I didn't do anything to address them last time. If the bubbles were small enough, do you think clear CA glue would work here? This would be over an opaque epoxy. 

[Tom King]

It will take some experimenting.  After epoxy is applied, I don't know why, but if you wave a heat gun over it, the bubbles float to the surface.

[Chestnut]

4 hours ago, TomInNC said:

Regarding the Rubio application, when I built my first epoxy-wood table, I asked them about the sanding progression, and they said to not take the wood beyond 180 because it would interfere with how the oil bonds with the wood. Rubio also indicated that you can take the epoxy to whatever grit you want because the oil effectively just lays on top of the epoxy instead of bonding with it. 

Yeah i don't know about this. I'd have to do some research but i have a gut feeling that Marc sands higher than 220 when he does furniture projects finished with rubio. Keep in mind that rubio is intended as a floor finish so the guidance from the company is going to focus on that aspect. Even flooring poly finishes recommend stopping at 120 grit which leaves a rough finish that may not meet the expectations for furniture. I had a detailed conversation with a Rubio sales man over exactly this. I asked him how non-abrasive smoothing (aka handplaning or scraping) would impact rubio if it is suggested to stop sanding at 180. I usually try and hand plane finish my furniture, and what grit is that? He didn't have an answer.

4 hours ago, TomInNC said:

I should have added that on my previous river table, when I noticed the flecks developing while sanding the bottom of the table, I opted not to sand beyond 220 and instead used Micro Gloss liquid abrasive and a Vlies pad to rub it in. I think I effectively skipped several thousand grit in terms of the suggested grit sequence for using the Micro Gloss, but I had a hard deadline on finishing the project for someone, and the epoxy looked very good afterwards, albeit with less sheen than I was hoping for. Since I'm not under the gun of a deadline for this build, I was hoping to do things right this time. Haha. 

I think this is a good technique but maybe just go further with the sand paper grits. If you sand over the epoxy onto the wood and don't want to roll the dice with rubio on 400 grit sanded wood, grab a hand sanding block and carefully scuff around the epoxy with 180 grit. you could also use some painters tape to limit how far away from the epoxy your sander impacts. If the edge of the wood and epoxy is crazy wiggly that may not work as well but for relatively strait sections painters tape could be a major help.

[Mark J]

Gettin' here late, but just want to mention that micro-mesh is a thing.

https://www.rockler.com/micro-mesh-cushioned-abrasives

The micromesh grit scale is different than FEPA (or CAMI), but these pads range from very fine to extremely fine.  

[BonPacific]

MIcro-mesh is great for polishing rounded shapes. It can easily cause divets or pillowing that you didn't intend though, so be careful using it if you want a flat surface at the end.

[Tom King]

Those look like the same ones sold on Amazon for $16

https://www.amazon.com/Sanding-Stopper-Polishing-Perfect-Materials/dp/B000H6EC4C/ref=sr_1_1_sspa?crid=36FWHZM3MHCW5&keywords=micro+mesh+sanding+pads&qid=1664484710&qu=eyJxc2MiOiI0LjM0IiwicXNhIjoiMy45MSIsInFzcCI6IjMuODcifQ%3D%3D&sprefix=%2Caps%2C128&sr=8-1-spons&psc=1&smid=A7O51HGOUZ91S

I bought them to see what they were like, but never used them much yet.  They seem okay.