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Does Drying Turner Speed Matter?
22 replies to this topic
Posted 30 March 2009 - 01:47 PM
I have a question I can't find an answer for anywhere. Maybe some of the physics experts like Vodkaman can help.
Does the speed of the drying wheel make any difference in the outcome of the finished clear coat?
I have used a small motor that turns at 6 RPM for about 2 years with great results. It only does one bait at a time and it turns on the axis of the bait. I always got a smooth even finish.
I recently made a turner with a 2 RPM motor that allows me to do up to 8 baits at a time. They turn on the axis of the center dowel and the baits rotate areoun it. I am now getting lumpy results and sometimes even a large clump in one place, and it is not an even finish all over the bait.
All of it is with D2T clear coat.
Posted 30 March 2009 - 02:11 PM
It is not the rotation speed alone that is important, but rather the combination of the speed and the diameter of the wheel. Think of the fairground ride which uses centrifugal forces to pin you to the side wall as the floor drops away. The rotation speed is not that great, but the diameter is large.
I have only used a variable speed drill for the very few D2T applications that I have done. I could not get the rotation less than 60rpm, but the bait was axially mounted, so the diameter of the wheel was very small, only half the depth of the lure body. The D2T levelled just fine.
My personal opinion is that speeds much higher than 6 rpm could be tolerated, but I have not tested this idea and I am happy to conform to the experience of TU members. Do not be afraid to experiment. If your motor does 20 rpm, build a wheel and try it with test pieces. If it does not work, reduce the diameter that the lure is mounted. This is a lot easier than trying to gear the motor down.
Posted 31 March 2009 - 08:10 AM
I've found that too fast defeats the purpose of the drying wheel, which is to prevent epoxy from sagging due to gravity.
If the lure is rotated too fast, the centrifugal force is so strong it does the same thing as gravity, "throwing" the epoxy to the outer most side.
A low speed motor, 1 rpm, is plenty, if you're making a Ferris wheel type drying wheel. The faster the motor, the smaller the diameter of the Ferris wheels, or you'll have the epoxy moving out to the outer facing sides. The same thing with single spindles and lure clamps. The faster they rotate, the stronger the force on the epoxy to throw it out to the end of the lure.
When I decided to build a drying wheel, I bought a rotisserie motor and spit replacement kit from a hardware store, and the motor was 1 rpm. Happy accident.
I made a Ferris wheel dryer with two 16" diameter wheels, and can coat 8 jointed lures at the same time. If I'm feeling ambitious, I could adjust the wheels far enough apart to accommodate two lures in tandem, but that's more work than I care to do.
When I used to coat lures with D2T, I would turn them by hand for the first 30 minutes, and then just hang them.
One thing I remember is that sagging is more common if you put on too much epoxy, no matter which method you use. Especially with D2T. It's already thick to begin with.
Posted 31 March 2009 - 10:47 AM
Another way to describe the 'ferris wheel' effect is to think of the old vinyl record album players. Depending on the size of the record, it needed to be played at different speeds. They all had the same RPM's, but the further out (or bigger the album), the more speed produced.
Posted 31 March 2009 - 02:20 PM
Dave, I'm having a hard time with what you're writing. I try to read most of the posts here on TU forum and you've always come across as someone who knows what he's talking about:worship: so I hesitate to post this, but I thought what the heck, I might learn something.
You mention centrifugal force as one of the important aspects of a drying wheel. I am of the opinion that the only thing a drying wheel does is keep the epoxy from sagging on the bottom a lure that is hanging stationary. How fast must a drying wheel have to turn for centrifugal force to become a factor? I can't help but thinking that a lure would have to move very fast to overcome the epoxy's viscosity not to mention the force of gravity. Additionally, if the velocity of the lure is such that centrifugal force is affecting the liquid epoxy, wouldn't it force it away from the center of the travel and gather on the lure in the same place until cured, giving it the same appearance as sagging epoxy?
This is clear in my mind I just hope it's clear in writing. If not I blame over indulgence of chemical compounds and the science of fermentation .
Posted 31 March 2009 - 02:53 PM
Justwannafish. You are correct to question what I wrote. I always have problems getting my message across, so best ask.
Centrifugal force is what we are trying to avoid. All we want to do is invert the lure and get an even spread of top coat.
If rotation is too slow, sagging will occur, if too fast, the centrifugal forces will throw the top coat outwards.
It has already been stated that manually inverting the lure every few minutes works, That is effectively one rotation every 3 minutes. We also know that 6 rotations per minute of a average diameter wheel is OK too.
Marks wheel of 16" diameter will have a successful outcome of 0.3 rpm to 6 rpm, proven.
The reason that drying wheels commonly used are 1rpm, 4rpm and 6rpm, is that those are the commonly available motors, ie microwave, rotisseri etc. after that, the next most common speeds are 30rpm and 60rpm.
I am suggesting that even a 60rpm rotation with an 8" radius, is not going to generate enough innertia to be a problem.
experiment: take an 8" length of chord, tie a 1/2 oz weight to it and spin it. How fast must you rotate it before inertia takes effect? Even at 60rpm, you will not get the weight to spin, gravity will win.
There has been lots of talk about rotation speed for drying wheels, but no one has really pushed the limits to find out where the limit is. All I am saying is that the speed limit is a lot higher than you might think.
Posted 31 March 2009 - 03:06 PM
See there, all you had to do was make it clear enough for a two year old to understand and it becomes clear to me. No matter how I pictured it, I couldn't make sense of centrifugal force induced by the turning wheel actually aiding in the smooth application of epoxy.
If anyone is brave enough to spin a wheel fast enough to 'push the envelope" when testing a drying wheel let us know what you come up with.
It may be more fun to hear what you find out is too fast
Posted 31 March 2009 - 03:17 PM
It is true, I need an interpretor. Usually one of the TU members will step in and write two lines and clearly explain what took me 8 paragraphs to write.
The big problem is that motors are expensive. I have a 30rpm and a 60rpm motors in front of me, but sorry, I have way too many other projects on the go, to take on this one. I'll add it to my list.
It is definately an experiment that needs doing, just to put this long standing issue to bed once and for all. Arguing between the merits of 1 rpm and 6rpm is nonsense, in my most humble opinion.
I'm going to use propionate, so I don't even require a wheel, but I find the subject fascinating. Maybe I shouldn't get involved.
Posted 31 March 2009 - 07:05 PM
I spin mine head over tail and if it goes too fast or too slow you will notice epoxy gathering at each end of the lure.
Posted 02 April 2009 - 10:30 PM
The trick is to rotate the lure fast enough to make the effect of gravity on the epoxy even, but not so fast that it throws the epoxy to the outside.
I often wondered if the type of lure dryer that holds the lures in a radial position, like the spokes of a wheel, would have more problems, especially at higher speeds, due to the different speeds of the lure as you travel out away from the central axis. Like the increased centrifugal force you feel on a merry go round as you move out from the center.
But enough people use that method that it must not be a problem.
Posted 05 April 2009 - 12:20 PM
Thanks to everyone for the comments and help!
The speed of the wheel DOES matter as I have found out.
I was drying with a 9 RPM motor one bait at a time and turning on its own axis from lead hook eye through the end hook eye. Each bait was truly turning at 9 RPM. It was working well, but I wanted to be able to do more than one at a time.
I bought one of the motors someone told us about on this site on sale. It turns at 2 RPM. I made a wheel that can handle 6 baits and each are 7 inches from the center axis and rotating around the it. The results of this speed and distance was that each bait actually turned at 1.3 RPM around the center axis.
ALL my baits came out lumpy and uneven with this set up.
I took the 9 RPM motor and put it on my new wheel.
Now each bait goes around the center axis 7.6 times per minute. This has now fixed the lumpy D2T issue. All baits are smooth again.
My conclusion is that you can turn baits too slowly and thereby NOT overcome the effects of gravity on the relatively heavy D2T. After all that is the purpose of the drying wheel.
I would think from my experience that someone would not want to turn a bait slower than 5 or 6 RPM to be confident in the ability of the wheel to help with the leveling of the clear coat.
I don't want to repeat the experiment to find out what is too fast to turn a bait. 60 RPM seems very fast to me, and my wife would kill me if she came into the garage one day and there was glue slung all over her car.
Thanks for the help and discussion. I love this site.
Posted 05 April 2009 - 12:35 PM
I forgot to add this picture of the wheel
Posted 05 April 2009 - 03:03 PM
Dubs, thanks for the feedback.
I am not saying 60rpm would work, but at the end of the day, it is only 1 turn per second.
The ultimate drying wheel experiment is on my list, half way down the second page. If I find a suitaable motor and some D2T, I would probably bring it forward, as it is an easy experiment to do.
Posted 06 April 2009 - 10:06 AM
Thanks for sharing your experience with D2T. I haven't ever turned a lure that I coated with it, so I am glad to learn your info. It seems that, in the case of D2T, you need the wheel to turn faster to overcome the stiffness of the epoxy.
I have never tried a wheel faster than 1rpm, so I'm glad to learn from you post.
I use Nu Lustre 55, which is the same consistency and has the same characteristics as Etex, as far as how it's applied and turned.
I found that I need the epoxy to be relatively stiff when I apply it.
When I hit the lures with a hair dryer while they turn, the epoxy will fish eye very badly because it is so viscous when heated.
Posted 06 April 2009 - 11:43 AM
I clip lures on my wheel by the lip with alligator clips and it turns at 4 rpm. No problem with centrifugal force moving the epoxy or any sagging that I can see. And 4 rpm is just slow enough that you can clip lures on while it rotates. I don't spin lures coated with Dick Nite. It just isn't necessary and spinning them can actually make the DN pool in one spot and cause the paint to bubble or wrinkle. I just coat them and hang them so the excess drips off the tail.
Posted 06 April 2009 - 06:17 PM
Okay this is off topic but I'm new on this site and can't figure out how to start a new thread. Any help would be great.
Posted 06 April 2009 - 07:01 PM
There is a [New thread] button just at the top of the window where all the threads are. It is on the left side.
Posted 06 April 2009 - 09:51 PM
Does it matter if a crank is on a drying wheel vertically or horizontally