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Final finishing.

Posted: Sun Dec 20, 2009 6:41 am
by Johnny Rotten
Ok so I've done a number of boards now, and in each case I get stuck in the final finishing stage until I finally lose patience say F' it, it's good enough. leaving lots of pin holes. I figure I've found the hard way to do it , so would love someone to show me a better way to get a good surface finish. .

Here's my set up bottom to top.
Rocker table,
Glass
foam
Glass
perforated peel ply
breather
Vac bag.

Usually to get a decent surface finish I end up doing the following.
Top:
Sand
fairing, (epoxy + cabosil + micoballoons)
Sand (find lots of bubbles and pinholes)...possibly repeat fairing if too many bubbles.
primer
glazing compound.
sand
primer
paint

Bottom
Sand
primer
glazing compound
sand
primer
paint.

I can shape and build a board in less than 5 hours but the finshing is killin me. Don't like the idea of a hot coat as it's just using pure epoxy as a fairing compound (Heavy)

Re: Final finishing.

Posted: Sun Dec 20, 2009 10:32 pm
by BWD
If the glass is surfboard type, 4-8oz woven, the resin is literally only an ounce or two, some or most of which gets sanded off, not a big deal. Millions of surfboards done this way, it's not that bad....
To fill heavy weave like in some stitched glass I'd use phenolic microballons in a "ketchup" blend.
Reduces weight a good bit, still strong enough probably although some would say it is better to fill with straight epoxy for strength.
But to each his own.
Depending on epoxy viscosity and weave, it can be better to do several thin coats of "hot coat" applied while preceding coat is "green," at least then you can have fewer sanding/fairing stages...
I tend to get frustrated with the time in finishing too...

Re: Final finishing.

Posted: Mon Dec 21, 2009 6:42 pm
by Johnny Rotten
Thanks bro,

After looking at how much primer, filler and glazing compound I I used, I'm certain that I'm way better off if I can nail it with a good hot coat to get a perfect surface finish, and the viscosity would fill the pin holes in the weave better.

If that doesn't work ketchup like consistency seems to be a better plan, currently I've been shooting for bondo like consistency, which has been a bitch to get even coverage and doesn't fill the pinholes that well.

I never worry about the strength of the hot coat, The fibers give the strength, if relying on you're fairing compound for strength, your lay up schedule needs work in my opinion.

Much appreciated.

Re: Final finishing.

Posted: Sat Feb 20, 2010 9:54 am
by mthboards
I put the glass down then put one good sanding coat on it and almost sand it down to the glass with 60 grit. Then I put an extremly thin finish coat of polyurothane just to get ride of the scratches.
Then its 800 grit then 2000 grit, then rubbing compound then polishing compound takes me a good 4 hours to do both sides. http://WWW.MTHBOARDS.COM

Re: Final finishing.

Posted: Fri Aug 27, 2010 8:57 pm
by Rando
wow, nice stick. how does it ride?

Re: Final finishing.

Posted: Wed Sep 01, 2010 6:53 am
by swim82
mthboards wrote:I put the glass down then put one good sanding coat on it and almost sand it down to the glass with 60 grit. Then I put an extremly thin finish coat of polyurothane just to get ride of the scratches.
Then its 800 grit then 2000 grit, then rubbing compound then polishing compound takes me a good 4 hours to do both sides. http://WWW.MTHBOARDS.COM

really nice board, I just started making a cedar board
how do you make you rocker hold with the full glass boards?
do you put a strip of glass running the whole lenght but just in the middle while holding the sides to the rocker table with clamps? if so, do you glass over the strip after?

second question, how much more rocker do you put in ceder to get the rocker you want? for example, do you glass witha 2 inch rocker to get a one inch rocker once you unclamp it?
thx

Re: Final finishing.

Posted: Wed Sep 01, 2010 6:54 am
by swim82
mthboards wrote:I put the glass down then put one good sanding coat on it and almost sand it down to the glass with 60 grit. Then I put an extremly thin finish coat of polyurothane just to get ride of the scratches.
Then its 800 grit then 2000 grit, then rubbing compound then polishing compound takes me a good 4 hours to do both sides. http://WWW.MTHBOARDS.COM

really nice board, I just started making a cedar board
how do you make you rocker hold with the full glass boards?
do you put a strip of glass running the whole lenght but just in the middle while holding the sides to the rocker table with clamps? if so, do you glass over the strip after?

second question, how much more rocker do you put in ceder to get the rocker you want? for example, do you glass witha 2 inch rocker to get a one inch rocker once you unclamp it?
thx

Re: Final finishing.

Posted: Wed Sep 15, 2010 4:12 am
by SweetDoug
Beautiful. What do you use for the edge/rail of the board and how do you do it?

Doug

Re: Final finishing.

Posted: Wed Sep 15, 2010 5:11 am
by twah
you could also run a layer of s-glass overtop and make your layup a little more wet than usual. but just a little so everything really gets filled in

then just sand and polish down that s-glass layer till shiny. most of it will end up gone but its like 2-4 oz or something and not intended to add strength when you do it like that.

finishing is a bitch, but even if your board ends up all scratched and pinholey and shit, as long as it rides well you'll be fine. plus odds are you'll build another soon anyways and you can try again :P

Re: Final finishing.

Posted: Wed Sep 15, 2010 4:16 pm
by SweetDoug
What is "s-glass"?

Doug