the finish is in the prepwork ..........
Posted by: pilotwingz on Dec-13-12 8:04 AM (EST)
-- Last Updated: Dec-13-12 9:03 AM EST --
...... you've chosen well with the 3M Vinylester filler . One of my favorites for boat hull work .
Tip ... don't use "too much" of the blue catylyst cream , and only mix a golf ball size (max) at one time (a little less than a 3/4" line of it on a golf ball size of resin putty works just as good , maybe better , it will set almost as fast , don't worry !!) . This 3M Vinylester filler sets up fast , which is good cause you can be sanding out (faring) your fill and going over it again in 10-12 mins. in warm temps. .
Get yourself a 1/2" piece of smooth plywood about 16" x 8" to use as your mixing board . Scrape any remainder of the mix off your mixing board before it sets up (use a wider blade for that , like a 4"-6" drywall knife) , be sure to sand the board just before mixing next batch .
You'll need a "stiff" 1-1/2" putty knife for the mixing , and the the same putty knife can be used for the filling on the hull ... tip , wipe yor knives w/acetone before the stuff hardens on them , and lay the knives on the sander to "clean them better" before next mix and fill session . You must have very clean knives to do the filling , cause you use one knife to hold the mix in one hand , and the other to scrape a bit off of the holding knife for the other hand to do the filling , a two handed two knife job . !!
You should have a random orbit sander , I consider it a necessity . A Dewalt 5" is a good one . This will make all your mass sanding (including the mixing board) much faster and easier on you .
Sand by hand any detail areas that may have profiles the sander can't accomplish (sharp chines , stem radius , etc. ... it's very helpful to wrap the sand paper around various block shapes such as a 1-1/2" x (6" long) x 3/4" , and a 3" x (4" long) x 3/4" . These will work nicely for long sanding strokes , similar to how a hand plane is used on wood .
Another tip is to go over your filled areas with gelcoat . Just use the gelcoat the same way as the 3M filler , apply and sand fare . This works as a finer filler for very small pin holes , etc. . You will find that filling an area more than once works best . This way you can build up to what you want as opposed to trying for a one fill and sand approach (although that works fine on some areas) .
#80 to start sand out smoothing , #150 to refine , #220 and even the occassional #320 to refine the smoothness for finish ... You can get 5" sand pads for the sander in 5 packs (do it) , and you should have a few sheets of sand paper (#80 , #150 , #220) for the hand sanding work also . Just cut the sheets to fit snugly around your blocks w/a slight overlap on the up side .
Once you have your hull filled and fared to your satisfaction ... final wipe off w/acetone before painting . The acetone wipe should be done on a specific work area also after each sanding , or before next filling (buy a gallon and use disposable gloves) .
As for the painting ... the boat hull bottom paint is a good choice . A "Copolymer Self ablating" bottom paint wears itself away smoothly over time and is easy to re-coat in the future . I thinks it's the way to go because it's tough stuff and can be found reasonably inexpensive . If using the ablative bottom paint it's important you make sure it is a "Copolymer" ablative paint.
This link will bring you up to snuff on the ablative paints .
oh yeah almost forgot ... give the hull a good sanding out with the #80 and #150 and then wipe w/acetone ... "before" starting the fill and faring process (bet you figured that already though) .
A good prep job is important (I think) . It's not a hard job but it takes a bit of time cause of all those fills and faring out . Expect to have several individual fill and sand sessions (several different days of work) . You appreciate the time you spent up front doing the prep when you see the outcome of the easy job ... the painting .
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