PDA

View Full Version : Epoxy coatings - slow-turn motor for lathe



Robert Marshall
05-09-2019, 11:49 AM
I'm thinking about using epoxy to coat some pieces. I've seen it done by the Moulthrop family woodturners, with amazing (and pricey) results.

I believe the key to making this work is to slowly rotate the pieces, so that the epoxy doesn't run or drip off, until it has cured. In effect, you provide a zero-gravity simulation, where the force of gravity is constantly changing direction for any given point on the object, over the 360 degrees of rotation, cancelling itself out.

Has anyone here done this, and if so, what do you recommend as to (1) the RPM of the motor that you would use, and (2) means of engaging the motor to the lathe spindle (temporarily, while the object is being rotated).

I've heard of people using rotisserie motors from old gas grills, but I don't have one to scavenge from.

Thanks.

Robert

Wes Mitchell
05-09-2019, 12:24 PM
You could take a look at they use for building fishing rods. Drying the epoxy that holds the guides in place is a very similar process. I always used Angler's Workshop.

Brice Rogers
05-09-2019, 1:01 PM
On some pieces where I have wanted to have a very high gloss, I have applied up to perhaps a dozen coats of Wipe-on poly (oil based). I keep the coats very thin, apply them with a cosmetic sponge wedge and rotate the piece for perhaps 2 or 3 minutes to avoid runs or sags while it is initially curing.

My lathe goes down to about 60 rpm, so that is the speed that I use. It seems to go very well and it has virtually eliminated runs and sags.

I did a google search for rotisserie motors and came up with some kits that are used for applying epoxy to cups:

https://www.amazon.com/dp/B07QDRB16S/ref=sspa_dk_detail_5?psc=1&pd_rd_i=B07QDRB16S&pd_rd_w=Q7NOe&pf_rd_p=46cdcfa7-b302-4268-b799-8f7d8cb5008b&pd_rd_wg=CwLhJ&pf_rd_r=P99054TZ8Y5ZCSVWGD32&pd_rd_r=71a4dd4e-7279-11e9-a5e3-c7fc26cb216e

As far as coupling a slow speed motor to your existing lathe, I'm sure that there are a dozen or more different ways to do that. But not knowing what lathe you have, it would be impossible to suggest which method would work best for you.

Steve Eure
05-09-2019, 2:49 PM
I have a rotisserie motor from Lowes that was fairly inexpensive. I took a small piece of key stock (1/4" I believe) and coupled it to a threaded bushing that screws into the headstock of my Laguna 1836. It turns very slowly and works like a charm. I had a similar setup on my midi before the larger lathe and had to loosen the belts on that one while turning with the patisserie motor. Not so with the Laguna. It spins nicely and at the right speed.
The rotisserie motor sets perfectly on top of my lathe motor and the lathe motor fan housing keeps it from coming off. I didn't have to make a bracket for it.

Steve Eure
05-09-2019, 3:35 PM
Robert, here are a few images of my set-up.
Hope this helps to give you some ideas.

409566 409568 409567 409569

roger wiegand
05-09-2019, 5:23 PM
My lathe will slow down to a couple rpms with the speed controller and motor it has. I've frequently used it when finishing Lefty's Deceiver's. Never tried it for a piece of wood though!

409571
"It's no use if it ain't got chartreuse!"

robert baccus
05-09-2019, 11:00 PM
Slow turning should help smooth application on straight objects but pieces with various diameters will probably mess up the process. Rpm and centrifugal forces are not the same on different diameters. But give it a try and share with us.

Robert Marshall
05-10-2019, 8:17 AM
Thanks to all who have chimed-in.

I've bought a small 5-6 rpm motor through Amazon, and I'm going to try linking it up to my Grizzly, to see if I can do some epoxy-coating magic.

My guess (hope?) is that at 5-6 rpm (10 to 12 seconds to do a full rotation), the amount of centrifugal force will be minimal, relative to the force of gravity (which will itself be cancelled out by the rotation). In other words: we will see how it turns out! May report back here.

Barry McFadden
05-10-2019, 10:49 AM
I have a rotisserie motor from Lowes that was fairly inexpensive. I took a small piece of key stock (1/4" I believe) and coupled it to a threaded bushing that screws into the headstock of my Laguna 1836. It turns very slowly and works like a charm. I had a similar setup on my midi before the larger lathe and had to loosen the belts on that one while turning with the patisserie motor. Not so with the Laguna. It spins nicely and at the right speed.
The rotisserie motor sets perfectly on top of my lathe motor and the lathe motor fan housing keeps it from coming off. I didn't have to make a bracket for it.

I'm interested as to why you hook a separate motor up to your Laguna 18/36. I have the same lathe and I just set the speed to 50 rpm and put on my WOP and let it run for about 10 min to set up and never get any drips or runs.

Steve Eure
05-10-2019, 3:01 PM
Barry, I do the same with WOP. But with epoxy, whenever I've used it, it has a tendency to sling off at higher speeds. The slower rotation takes care of that and keeps the epoxy flat on the work piece.

jared herbert
05-11-2019, 10:01 AM
We just happened on to a guy that wa making custom fishing rods . He had
rigged up an old grill rotisserie with a rack that held 8 rods
and then it slowly turned while the coatings on the rods
cured. The funny thing was that he was set up on the music
stage in one end of the bar that he owned. He made rods while
the drinkers were at the other side of the room doing what they do.
it was also a set up bar, a real step back in time.