Question for the sanding experts

Guys, I sanded my hull for two hours last night with 80, then 120 grit.  I started with the RO sander and then by hand.  The hull will be primed with Interlux Pre-Kote and then Brightsides paint.  Does this look close, or do I need more work?


7 replies:

« Previous Post       List of Posts       Next Post »

RE: Question for the sanding experts

You can definitely see some glass in some areas and lots of little pits.  I think I may need to go over some areas with a thin coat of epoxy.  I do know I have not gone into the glass.  I can wipe it down with water and the weave turns clear.

RE: Question for the sanding experts

I would sand a little more to get rid of the pits... that said you need to be careful not to sand through the glass but is sounds like you are already beinf careful of that.  If you cannot get rid of the pits without getting in to the glass, then another coat of epoxy might be in order. 

temper all of this with the balance of effort & perfection.  Since you are painting, you can "cheat" and use micro balloons for fairing, makes for easier sanding.

RE: Question for the sanding experts

Thanks David.  I have some West 407 fairing filler (micro balloons).  I believe I will mix that with some of my left over MAS epoxy and hardener and go over the hull once more.  I'm told that I can use the West 407 with the MAS since the 407 is just a filler.

RE: Question for the sanding experts

More sanding... I would not add filler or fairing compound as it will just add weight and use more epoxy. sand the center of the panels staying away from the edges until the end. You may need one more coat but it will be a thin one. Pre-Kote Primer will fill in the small spots before you paint.

RE: Question for the sanding experts

The pits need to go. If you can see the weave, then obviously you are close but may not have cut through to the cloth yet. Getting close is good, since excess epoxy on top of the cloth just adds weight. Sometimes you can see little 'hairs' sticking out of the epoxy when you have gone to far. If you wet down the area and the weave disappears, then this is what you will see after varnishing.


I don't use an electric sander anymore, preferring the control of wet sanding by hand, starting with 80 grit to bring down the bumps and finishing with 180. Wet sanding is also an excellent way to target specific spots such as your pitted areas.

Good Luck


RE: Question for the sanding experts

Do not use the micro balloons...they have the effect of hardening the finish so you will have a tougher time sanding. Use a coat of epoxy to fill the pits and remaining exposed weave. Apply another coat of epoxy if the pits don't get filled after the last coat. Apply the epoxy only to the areas affected, that will reduce the amount of sanding you will need to do.


Robert N Pruden

RE: Question for the sanding experts

Hello Guys, I actually did some more sanding on the hull with 120, 220 and even 320 wet.  It was getting close to the glass in a lot of areas, and there were still some tiny pits.  I am sure those pits would have been filled in by the Pre-Kote primer, but I did add a thin layer of epoxy to the those areas. 

« Previous Post     List of Posts     Next Post »

Please login or register to post a reply.