Our workshop was mostly equipped a couple months ago and the work on our third-generation massage tool prototypes is now nearly complete. There have been many lessons learned and a delay with each. One of the trickiest things I’ve struggled with is getting a gloss finish using Krylon clearcoat. I found a number of helpful how-to discussions on the Internet but every project is different and I don’t think there is a perfect recipe that will serve everyone. What I learned is that the crazy guy in a forum who said it required 18 coats was right.
Some of the mistakes I’ve made:
- waited too long to buy a respirator at Home Depot – they’re inexpensive and work really really well.
- sprayed clearcoat outside on a windy day.
- stuck too long with hand sanding (get an orbital sander).
- wet sanding and alcohol cleanup made a sticky mess even though 24 hours had passed from the last coat.
- wet sanding did not allow me to see the surface patterns.
- sitting the prototype on its bottom for every coat caused an uneven thickness because of the curves involved
- 220 grit sanding in between coats was too aggressive.
- moving on to find grit sanding before and adequately fixed coat was developed, picture on the right – notice part of the surface shines where the code is thick enough and the other part has a matte finish where the coat was not thick enough.
So here’s the formula I’ve come up with:
- 4 light coats separated about eight minutes apart
- dry sand with 600 grit the next day
- 4 more light coats, new position (upside down)
- dry sand with 600 grit the next day
- 4 more light coats, new position (rightside up)
- dry sand with 600 grit the next day
- 4 more light coats, new position (upside down)
- dry sand with 600 grit the next day
- 4 more light coats, new position (upside down)
- dry sand with progressively finer grits to 2000
- buff with rubbing compound
- buff with swirl remover
Other notes:
- 3M’s very fine foam backed sandpaper rocks!
- the foam sanding ball can be covered with foam backed sandpaper using a rubber band – great combination!
- gluing layers of wood together works really well but do one layer at a time because Elmer’s wood glue sets up way too fast
What’s next? I’m waiting on the weather to warm up to 50° so I can spray more coats and waiting on a new hook and loop orbital sander and some super fine grit discs to go with it. My hands became so sore from the sanding that I had to take a break for a couple days. often my neck and shoulders get sore from looking down as I work. Fortunately, I’ve got just the right massage tools and they work every time!