Bottom Refinishing Questions

[BigDiesel]

I am prepping the bottom of a 23 ft fiberglass cruiser whose previous owner would beach the boat in sand and/or clay. I will use the Interlux system (Surface Prep YMA601, Interstrip 299E, Epiglass HT9000, Watertite Epoxy Filler, Interprotect 2000E, and Micron CSC).<br /><br />My questions regard the (1) amount of sanding required and (2) the build up of missing gelcoat.<br /><br />(1) This is the Hull Surface Abrasion. When I sand this with my random orbit sander, I will have to cut quite a bit into the gelcoat to remove most of the scratches. My question is, what do I do to recover this removed gelcoat? I did not place a rule in the picture, but the repair area is roughly 3 ft wide and perhaps 5 ft long.<br /><br />(2) This is the Chipped Gelcoat on Keel. I assume that I after I Epiglass the area, I slowly add individual layers of Watertite epoxy to the height of the existing gelcoat?<br /><br />This is my first work with epoxy and gelcoats so please explain your suggestions in layman terms.

 

[Paul Moir]

Re: Bottom Refinishing Questions

I'm responding mostly to bump it back up to the top. I have very little experience with gelcoat repairs. But if you don't go all the way through it, I don't see why you would need to build it up for thickness again, it's just there to look good.<br /><br />As for the bottom, with a fairing filler which is easily sandable like Watertite, I usually build it up thick and then shape it with a palm sander. It's hard to make it the right shape the first time and you'll have to do a couple coats if your running thicker than about 1/2" or so. I assume the Micron will get painted over it.<br />Now personally I just mix up my own fairing compound out of epoxy and a micro/mini ballon filler like HT330. That way I can set whatever consistancy I need.<br /><br />Be very careful working with HT9000. The pot will get burning hot in just a few minutes and set up on you. The trick is to mix thoroughly but quickly, and get the compound spread out as fast as you can. Then work it into shape. The more spread out it is, the cooler it will be and the slower it will cure. Even a 1/2" left in the mixing pot will get smoking hot and be rock hard in 20 minutes. The spread out stuff will be workable for almost a half hour. Depending of course.<br />EDIT: I thought HT9000 was the fast hardner. I guess they call the resin and fast and slow hardener HT9000. The above does not apply nearly so much if you're using the slow/regular hardner.<br /><br />You might want to try refridgerating the resin & hardener before you mix it up for the first time to acheive a longer pot life. Start with a small batch until you get used to it.