by cgdm1168 » Fri Jan 16, 2004 5:04 pm
Back to painting:
I stripped my Robin Yachts Hull to bare gelcoat(using "Bulldog Bumper Stripper- Worked great, fast, and all but eliminated sanding and is fiberglass safe), as part of my refit. Instead of the normal primer and paint I decided to use "Kyrlon Fusion".(The new "plastic safe paint"). Very good results for a primerless paint. Unfortunately, I did a poor job of masking my work and came up with a grossly distorted waterline. (Port was set for a 43 inch, and starboard for a 42 inch. ( I discovered this after I had already colored sanded with 1000 and 1500 grit wet/dry paper and used polishing compound.(Note to self, ensure that worktable is level in all directions and boat is properly secured. Also, don't trust eyeballs, they lie while rulers don't).
I considered totally stripping the hull, re-applying freshpaint, but got a wild idea instead. I laid the new waterline much more carefully, then rough sanded to 400 grit paper, and repainted the entire under-waterline section of the boat as before. I was anticipting at least a 5 day lay-up before I could go through the wet sanding and polishing, and laying down the above waterline paint.
As my hull was laid up with fresh paint, and wasn't ready for color sanding, I decided to test a theory on the freshly painted rudder (only about 1.5 hours since paint applied). I had a small paint run in her, but was pretty peeved abount having to sand it down completley and restarting. As the paint was pretty fresh, I thought about "heating" it to get it to flow a bit, and see if I could reduce the run.
I used a "monokote heat gun", that I had laying around. (from my failed RC airplane covering attempt). I set the temp to high and adjusted the air baffle to create as hot an airflow as I could. I slowly heated the run area with constant motion of the nozzle, and found that the paint seemed to "flow" and level out. Great. I then swithed to a cold airfolw, and coninued. Not only did the paint "flow and level" It became increadibly smooth and almost glass like in appearance.(Great refraction depth)
After waiting for it to totally cool, I tested an inconspicuous area. It was increadibly hard. I guess the heating had speeded up the curing process considerably. As good as the results were, It looked like I could skip the 1000 and 1500 grit wet sanding, and go right to the polishing compound. I did, and it came out better than my tradional approach.
I tested this on the hull, and found that if you carefully spray this paint in mulitple light coats until a slight gloss is acheived, then wait for about 2- 3 hours, then use the heat gun to harden and "flow the paint" you will get a near mirror like finish that will only require use of a polishing compound and not a full sanding.
This seems to give great results, requires no primer on a clean hull, and speeds the process, at least in my case by a good 5 or 6 days, and greatly reduces the labor involved.