Earlier this summer, I found the awesome tutorial about the Massey finish by Kevin @ Harvester Calls. Great Tutorial, and well worth the read. He covers so much about this great finish and really does a great job explaining how it works and how to get started. I used it and finished a bunch of calls so far this year. Link below if you need it:
http://thogamecallsforums.com/index.php/topic,19990.msg151035.html#msg151035However, I'm always trying to learn and perfect my own way of doing things. I figured I'd put what I've learned about the finish up here so others could benefit from it.... Some of what I've put here is based on two different experience bases that I've had in the past - building composite structures (laying up fiberglass and carbon fiber parts with epoxy and polyester resin) and painting cars. The experience I got from doing those things for so many years was pretty useful in trying to improve my method here.
Interestingly, I did a pretty good job on the first batch of calls I did following Kevin's method, however the next batch was a disaster. I then had to sand those back down, re-do them and figure out why.
First thing up, I liked the
'finishing mandrels' that Kevin designed, but I needed to improve them to work better in my shop. I made mine from 5/8" oak dowel (to fit my barrels) from a big box store, and then turned a few thou smaller than the barrels. I added an o-ring to them to make it easier to get the barrel to stay on them. Finally, I added a cup hook to the end to allow me to hang my barrels from the wire racking that is all around my shop. This gets the barrels up and out of the way while drying.
Next up, I like to
keep my equipment clean, so I wanted to build something to do that with. The trap on the lathe is the bottom of a milk carton. Stuck to the bottom of it is a couple of refrigerator magnets that hold it stuck to the lathe. Wish I could take credit for that. I saw it in a Youtube vid, but don't remember who did it. It works and keeps the epoxy mix off the lathe. I use it for wet sanding and other finishing work too.
Next up was all the
prep work for the barrels. This is where the auto body work really came into play. Anyone in autobody will tell you that prep work is everything in auto finishing.
Just like any other finishing of a call, I spent a lot of time building up finish and then taking off the high spots again with steel wool. 400-600 grit paper will work, but it will gum up pretty fast. Additionally, the speed of the lathe is pretty critical here too. I like to take the finish down at about 700 rpms. The epoxy we're using in this finish does not like heat, and anything faster will generate heat. Clean up the work with a tack cloth before applying more finish, or you'll get dust and crap in the finish.
Next issue I tackled and probably the biggest issue for me was the
mix of the finish. I saw a couple different mixes listed and the benefits of each. Thicker is higher build and thinner is slower build. My suggestion is to go thinner no matter what. What I have experienced is that when you use a thicker mix, the epoxy will begin to harden more quickly on the part as you apply it. This in turn begins to pull fibers out of the fabric that you are using to apply the finish - resulting in a huge mess!
So, for the mix of the finish- IMO, 6 to 1 is better for application and will ultimately result in a slicker, smoother finish. This also allows the finish to be more self-leveling after running the application cloth against the part while applying.
How do you get a consistent mix? (where my composites experience helped) I mix my finish in glass jars thrown away from the kitchen. My kids love of jam has helped me here. The key to a consistent mix is a gram scale. I zero out the scale with the jar on it. Then pour each of the epoxy components in while on the scale, finally adding acetone to bring up the mix to the right levels. By zeroing out the scale with the jar on it, the math is really easy. I did a batch this morning with 4 grams of epoxy resin in it and went from there.
Application of the finish itself- to apply the finish, I have destroyed a bunch of old undershirts. They are worn out and soft and have no color in them to leach out because of the acetone. I make a little wad with a single, smooth outer surface. This prevents any streaks while applying. I run my lathe at its slowest speed (500rpms) and apply from one end to the other in one smooth motion.
A few other things I've tried...
5 Minute epoxy will work - However, compared to the 2-ton Devcon suggested by Kevin, the 5 minute epoxy feels 'rubbery' in the hand even a month later. It is most definitely fully cured, but it never gets the solid, hard finish (almost like a poly) that the 2-Ton Devcon gets. Stick to the 2-Ton Devcon or some other similar slow cure, heavy duty epoxy.
I have tried several things to work in small batches. I've basically given up on that. I tried some small 'Take and Throw-away' plastic containers that my wife uses in the kitchen. They were acetone safe and I was able to do a first coat with them. However by the second coat, the acetone had evaporated so much that the mix was probably down to 3-1 which was basically unworkable and just made a mess (time to start over!)
I hope some of these learnings are useful. As I mentioned at the top of the post, go read Kevin's excellent tutorial first, then read this. Finally, try the process!
