marine putty

[matt in miami]

hi ...Am rebuilding a kayak epoxied it and shaped it fairly well and then went to put a little coating of marine putty on it. Now Im sanding it with a 60 grit and man it takes forever.what is the best sandpaper you would se to get this stuff knocked down? Im used ot welding metal the grind then glass then a touch of bondo on the final shaping . This stuff is like rubber. thanks..

[Laoch]

I found 3m paper to be very effective at cutting through the gunk. I had to sand epoxy primer for months, literally like rubber, with 60 grit. It went on with a roller and looked like garbage, very thick even after being thinned to its max. I actually went with 34 grit above the water line to get it back to a uniform surface, then 60 grit and had to go back and putty like crazy in between sanding grits. I'm restoring a 30 ft. racing sailboat. Try using west system epoxy and add the fairing compound either 407 or 410. It's an ultralight microballoon that eases sandability. 410 is the lightest and good for large areas like your hull. I've been using 407 for the pinholes, pitting, and 34 grit scratches. Another tip: Through this expereince of sanding for months (large hull area) I found that changing the sandpaper from the sander and or block frequently makes the process go faster and you are less likely to burn out the sander and your arm. I just mixed up some west system putty thinnly as a glaze to get in the imperfections i did not see before on top of the base coat (dark blue) using a felxible card that comes in credit card junk mail. Now I am wet sanding with 220. I do a 2'x2' section then I change paper off the block. Plus I add dish detergent to the water in the bucket and let the paper soak for 15 min. for added felxibility. I will do a 320 wetsand after 220 and then 2 more base coats wetsanding with 320 inbetween and 600 on the final base coat before the clear coats. Hope this helps. Good luck.

[PAR]

I'd avoid using West System 410 only as the filler, it's difficult to flow out onto the surface smoothly, requiring additional fairing. Mix about 50-50 406 in with the micro balloons and the smoothing will be much easier. I use 407 for fairing as it's much easier to get a reasonably smooth coating with an applicator.

Change paper often, it does speed things up. I like 3M, but have had better luck with Norton's 3X brand. It has a cloth backing, so it doesn't tear easily and the abrasive is well stuck to the backing, plus it seems to last longer then other brands. It costs more, but this is typical of quality products.

[matt in miami]

thaks for the response micro balloons it will be then..