I've been doing repair work for a while now, and I do ok fairing, but there's room for improvement. I've got an early version of the Gougeon Bros book, are there others to consider? I've been using a variety of thin plywood boards with various grit sanding belts laminated to them, as long boards. Are there official tools available? Worthwhile? Using West's fairing filler usually leaves me with tiny pinholes that requires a lot of primer to fill, and not always successfully. My bodyman has recommended Dolphin glazing compound, which works well. But I wonder about it's long term compatability with epoxy, 'cause I'm pretty sure it's a polyester base. No problems so far, used under Flight Risk's automotive paint, now 4 years old and looking great. Anyone else have experience with similar products? Or techniques to deal with the pinholes? Other sage advice? Thanks of always!
dave
-- Have You Seen This? --
Re: Fairing advice/literature
[Re: davefarmer]
#188904 08/25/0904:14 AM08/25/0904:14 AM
My main problem with fairing the'32 has been getting the shape right, the convex shapes like the bottom of the hull are ok, its the concave shapes just above the waterline that are a pig.
i have sand paper tacked to all sorts of bendy boards/strips of pvc.
I was very worried about the amount of pinholes that showed up when my mate went over the hull with an airline before we started to paint on saturday. Not too much of an issue, because i am using awlgrip paints, once you have a coat of bullet-proof 545 primer on there, you can go over the hull with the awlfair filler and a scraper and the holles fill in really well. The awlfair is much less fluffy then the microlight and fills small bits better.
Paul
teamvmg.weebly.com
Re: Fairing advice/literature
[Re: davefarmer]
#188907 08/25/0904:28 AM08/25/0904:28 AM
Here are my tools of torture. #2 is a piece of pvc trim and gets across the curves[concave] #3 is a cut down 100mm drain pipe and is good for going along a curve
Paul
teamvmg.weebly.com
Re: Fairing advice/literature
[Re: TEAMVMG]
#188915 08/25/0906:12 AM08/25/0906:12 AM
I used 3M Pyrahna putty to fill the pinholes. It's a 2 part putty that is easy to use and sands easily.
Piranha Putty works very well for eliminating pin holes - and you can mix it so it kicks very quickly, which helps reduce cycle time on your preparation work (you can sand within 10 minutes). I only use this on shallow scratches or to eliminate pin holes in west system low density filler repairs. I use gel coat for repairs and have had no problems using this stuff. The guy whose shop Trey and I borrow uses Pirahna putty for final fairing and sprays Awlgrip - he has not had problems with this stuff.
You can buy additional 3M cream hardner at Home Depot if you use everything supplied with the product (I go heavy on the hardner to reduce cycle time 'cause I'm always short of time).
A lot of how you go about fairing depends on what your starting with. When I was building boats we built Kialoa IV. 80 ft boat built on a male plug. This means the outside of the hull is finished by hand. It took many months of sanding by three shifts to get the hull to spec. which was no more than 10 thousandths movement in a dial gauge with a sampling of about 6ft.
I would say that the standard board file will work on most production boat hulls.
I think the most important step in any sanding - fairing is to use a guide coat. We used Dykum Blue mixed with acetone and wiped the boat down with that or you can use flat black spray paint to dust a light coat over the area that your sanding. Chose your grit and sand. The highs and lows will be obvious. It will save you time because you will know when the hull is fair or when the sanding scratches are gone.
Leave the radius for last. Sand the flat areas first. Sand within a one foot high area sanding at a 45 degree stroke. Don't move too quickly down the hull but don't stay in one area too long. Decide if your goal is to take the highs down to the lows or are you going to fill the lows.
I use Evercoat filler. No pin holes. If you sand through to raw glass chances are you'll have pin holes in that area.
If your going to paint use a high build primer. 2 part. Epoxy or urethane. You can spray this primer over the pin holes then take a spreader and smooth over.
You can use anything over polyester. I would let the last coat of primer set for a week before sanding.
Like the post above what is your finish. It is always good to have a color guide. I Use West with 407 to make the shape. Then use a very thin smear coat wth 410 to fill pin holes. Next is paint small pin holes can be filled by using awlgrip high build primer. I try to stay away from poly fillers. But a two part glaze filler can be used over the primer by now the imperfections should be very small. Prime again, sand and you should have a great finish
Mike Shappell www.themanshed.com TMS-20 Builder G-Cat 5.7 - Current Boat NACRA 5.2 - early 70's
Excellent men! Just what I was after. I like the tools, seems like I'm on the right track there. And the suggestions for filling the pinholes is much appreciated. You guys are a treasure!
I have found filling pinholes is most easily done with the tip of your finger. Just rub in what ever product you are using for your application. I find this works with gelcoat too.
Collin Casey Infusion Platform + C2 rig and rags = one fast cookie