Glassing the hull

Glassing the hull

Post by Michele Hedderma » Fri, 10 Mar 2000 04:00:00


I built a Stitch n glue 17' kayak last year, and it's almost time for
another....
on the final  fill layer of epoxy over glass, how do i do it so i end up
with a SMOOTH, nicely filled fiberglass surface?? Last time I ended up with
a rough surface and sanded my heart out (for hours), occasionally sanding
down to the glass.... Any suggestions are welcome! thanks !!

 
 
 

Glassing the hull

Post by sailo » Fri, 10 Mar 2000 04:00:00

After the glass is wetted out, apply about 6 coats of epoxy over
it to fill the weave.  Apply the successive coats when the epoxy
is in the "green" stage.  Use foam rollers and back brush it to
smooth it out.  Remove any trapped air bubbles with a hair dryer.
 Before doing any sanding wash off the amine blush with warm
soapy water and a green scotchbrite pad or the blush will clog
your sander and make it very difficult for paint to stick.

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Glassing the hull

Post by JACQUES_MERTEN » Sat, 11 Mar 2000 04:00:00

That works but there is an easier way: use Hi-Build primer. Most marine
paint brands have a hibuild primer that fills the weave really well. It is
much easier to sand than epoxy resin.
We like the System Three hibuild or US Paints or Pettit.

--
Jacques Mertens
Boat Plans OnLine
http://www.bateau.com


Quote:
> After the glass is wetted out, apply about 6 coats of epoxy over
> it to fill the weave.  Apply the successive coats when the epoxy
> is in the "green" stage.  Use foam rollers and back brush it to
> smooth it out.  Remove any trapped air bubbles with a hair dryer.
>  Before doing any sanding wash off the amine blush with warm
> soapy water and a green scotchbrite pad or the blush will clog
> your sander and make it very difficult for paint to stick.

> * Sent from RemarQ http://www.remarq.com The Internet's Discussion Network
*
> The fastest and easiest way to search and participate in Usenet - Free!


 
 
 

Glassing the hull

Post by Michael J. Mille » Sat, 11 Mar 2000 04:00:00

I don't understand how the hair dryer will remove the air bubbles.

Mike Miller


 
 
 

Glassing the hull

Post by sailo » Sat, 11 Mar 2000 04:00:00

Anyone thinking of using epoxy should get the epoxy manual from
System 3.  Air that is trapped below the epoxy or that gets
entrained into the epoxy will leave a bubble.  A hair dryer will
pull the air bubble to the top and remove it.  For tough bubbles
a shot with a propane torch will get rid of those.  Heated air
rises, so that's how it works.  The heat also lets the skin of
the epoxy break like a balloon.  Epoxy is basically self
leveling, especially when warm, so the bubbles disappear.

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The fastest and easiest way to search and participate in Usenet - Free!

 
 
 

Glassing the hull

Post by Ernie Pawliu » Sat, 11 Mar 2000 04:00:00

Shouldn't the weave be filled first with epoxy for strength and to
provide a hard abrasion resistent surface. Then hi-build primer for
final fairing before paint ?



Quote:
> That works but there is an easier way: use Hi-Build primer. Most
marine
> paint brands have a hibuild primer that fills the weave really well.
It is
> much easier to sand than epoxy resin.
> We like the System Three hibuild or US Paints or Pettit.

> --
> Jacques Mertens
> Boat Plans OnLine
> http://www.bateau.com



> > After the glass is wetted out, apply about 6 coats of epoxy over
> > it to fill the weave.  Apply the successive coats when the epoxy
> > is in the "green" stage.  Use foam rollers and back brush it to
> > smooth it out.  Remove any trapped air bubbles with a hair dryer.
> >  Before doing any sanding wash off the amine blush with warm
> > soapy water and a green scotchbrite pad or the blush will clog
> > your sander and make it very difficult for paint to stick.

> > * Sent from RemarQ http://www.remarq.com The Internet's Discussion
Network
> *
> > The fastest and easiest way to search and participate in Usenet -
Free!

Sent via Deja.com http://www.deja.com/
Before you buy.
 
 
 

Glassing the hull

Post by Judy Moniha » Sat, 11 Mar 2000 04:00:00

Doesn't seem to be any magic, as far as I can tell.  You're sanding with a
power sander, right?  Use a random orbit about 80 grit.  Use the fastest
hardener you can handle so the stuff will gel asap and not sag. Tilt the boat
to keep as much as possibleof the boat  as level as possible and fill the weave
in sections.  Try not to sand into the fabric.  Add more resin layers (THIN!!)
so you can sand to smooth and not hit the fabric.  By the way, put the dry
cloth on the wood and apply the resin with a squeegee, stretching the fabric as
you fill the weave, and working away from your starting point.  Good luck!
Quote:

> I built a Stitch n glue 17' kayak last year, and it's almost time for
> another....
> on the final  fill layer of epoxy over glass, how do i do it so i end up
> with a SMOOTH, nicely filled fiberglass surface?? Last time I ended up with
> a rough surface and sanded my heart out (for hours), occasionally sanding
> down to the glass.... Any suggestions are welcome! thanks !!


 
 
 

Glassing the hull

Post by TRAC » Sun, 12 Mar 2000 04:00:00

Mike:

My understanding is that the heat softens (thins) the resin allowing the air
bubbles to rise to the surface.

Quote:

>I don't understand how the hair dryer will remove the air bubbles.

>Mike Miller


>^.att.net.POSTED!not-for-mail
>Xref: news.jps.net rec.boats.building:4123

>I don't understand how the hair dryer will remove the air bubbles.

>Mike Miller



 
 
 

Glassing the hull

Post by TheHo » Mon, 13 Mar 2000 04:00:00

I suppose it can't hurt to mention that the hair dryer trick only works to
remove bubbles from the resin BEFORE it hardens.  After it hardens, it's
sanding time.

John Hoaglund

 
 
 

Glassing the hull

Post by JACQUES_MERTEN » Tue, 14 Mar 2000 04:00:00

That's not exactly the problem. What happens is called "degassing".
Imagine that you cover cold plywood with resin. During the cure of the
resin, heat is produced (exotherm). Air trapped in the pores of the plywood
expands and tries to escape through the resin --> bubbles.
Solution: warm up the part before coating with resin.

--
Jacques Mertens
Boat Plans OnLine
http://www.bateau.com



Quote:
> I don't understand how the hair dryer will remove the air bubbles.

> Mike Miller



 
 
 

Glassing the hull

Post by Matt Hage » Fri, 17 Mar 2000 04:00:00

   Try using a scraper before you hit the sandpaper.  It's basically a
thin sheet (about 3" by 6" or so) of steel that you sharpen to put a
tiny burr on the edges.  When you drag it across the epoxy (or wood) it
cuts the high points and spans across the low points, giving a levelling
effect.  Sandpaper (with a soft pad) can dig down into the pits, which
doesn't solve the wavy surface problem.

Good luck.