I'm just finishing a new drying box and have some questions.

What is the ideal and maximum temperatures that I should get the box to? (I'm using LS Supreme)

I have a bunch of different RPM motors and I'm not sure which to use. This motor is strictly for drying, not application. What is the comprimise in RPM choice? Is thee a "too fast" or "too slow"?

Thanks for the help

Phil

Most finishes behave best at around 72 to 76 degrees, in my experience. Obviously you can deviate from this but both the viscosity of the fresh mix and the cure time will be affected. Cooler temps mean you are working with a bit thicker mix, but cure time is extended. Higher temps provide a thinner and possibly more maganageable mix, although for less time as the cure time is reduced.

My experience is that the mid 70's (F) give the best all around working mix and pot life.
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I think you mean what temperature to keep the drying box at rather than the finish when applying it, right?

I keep my drying boxes in the mid to upper 90s with four 40-watt bulbs in each one, and you can touch Flex Coat with the back of your fingernail in about three hours of drying at that temperature, and it's quite hard over night. The higher the temperature in your box, the faster the cure takes place (but remain within reason -- the 90s has never damaged any blank I've used and should not do so).

As for speeds, my dryers range from an 8 rpm motor to several 36 rpms. I prefer the slower one, but they all work fine.

I don't know if I am articulate enough to express this: The slower RPM motors allow the finish to flow completely around the blank as it turns. As the rotation rate increases, the "droop" cannot flow fast enough to catch up with the rotating rod and you may end up with high spots in the finish if the temp. is high enough for quick curing. For curing I have found that a 9 RPM motor works well & 75 deg. F to 90 deg a good curing temperature.

I hope this concept is slightly clearer than mud.

Gentlemen,

To further the discussion of drying speed, wouldn't you think that the motor speed you use is related to the relative viscosity (thickness) of the epoxy you are using? I believe that if the epoxy is relatively thick, you would use a slower speed on the motor to give the epoxy a chance to flow around the blank and level off. If the epoxy is thinner, I would use a higher motor speed to keep the thin epoxy "suspended" and keep it from sagging. Is my logic correct or am I not considering something?

Ed has brought up a good point and what we are finding is that the thicker finishes seem to work better at lower RPM's (6 to 20) and the thinner ones do better at higher speeds (40RPM and up). Some builders have told me that they are rotating at 60RPM's and getting some really good looking wraps.

But there is also a double-edged sword at work here. With the thinner viscosity finishes and the higher revolution speeds, finish is "slung" out and up the guide legs in some instances. Many have mentioned this as well.

I am not so sure that once you have your finish on the rod and appearing the way you want it, that reducing the temp it, rather than raising it, may result in better final results. Yes, it would take longer to cure at a lower speed, but it would also thicken to a point where it would not migrate up the guide legs and allow you to use a slower rotation speed in the process. This could be the best of both worlds.

I have not tried it but will make a note to give it a go at some point when I have more time.

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Guys,

Thanks for the input. You have hit my concerns about the relationship of temperature, curing time, viscosity and RPM. I suppose I will use a slower RPM motor for the time being.