Morgan Ohlson ) writes:

Which epoxy fillers do yo like the most?

use of some fillers is "counterproductive"
when resins are used to seal and protect wood.
resins protect wood because resins resist abraision.
that makes cured resins hard to sand because sandpaper is an abraisive.
so people add fillers to make the cured resin easier to sand smooth,
which makes the cured resisn less able to resist abraision,
which is why the resin was applied in the first place.



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On 23 Oct 2004 14:00:26 GMT, William R. Watt wrote:

Morgan Ohlson ) writes:

Which epoxy fillers do yo like the most?

use of some fillers is "counterproductive"
when resins are used to seal and protect wood.

Okej, okej... some love wood... ;o)

....but everything isn't wood )

resins protect wood because resins resist abraision.
that makes cured resins hard to sand because sandpaper is an abraisive.

Most people building in wood doesn't matter much about weight anyhow...
naturally the lite fillers and the EPS balls are aimed towards liteweight
boats of different kinds.

The balls could... if it works well. be appropriate to reinforece areas
around screw attatchments etc. It should be around 400% stronger the the
lite foams anyhow but only suitable for building ~0,7cm's or somthing
like that.

One could mix ~40% my-ballons with the larger balls ~30% and get a really
lite epoxy to build radius and /or make rounded shapes for ergonomy.

so people add fillers to make the cured resin easier to sand smooth,
which makes the cured resisn less able to resist abraision,
which is why the resin was applied in the first place.

No, thats why PU-coating is on top )

My 18' hull is at the moment at around 78Kgs incl. fittings and ballast
tanks. It looks a little like the Wayfarer but has a higher freeboard. I'm a
weigh****cher! The aim was at 70 with a limit at 80...

Morgan O.

On Thu, 21 Oct 2004 13:05:25 +0000, Morgan Ohlson wrote:

Epoxi is widly spread...

But, sometimes other traits are wished for. Are there any marine performance
(for wood, plastic, ,metalls) glues that (compared to epoxi) are more...

a) elastic?

Marine silicon sealant is elastic and flexible, and resists high and low
temperatures, but it is not a very good adhesive.


b) low density?

I don't think you can beat filled epoxy. Use West System ultralight
filler, for example, but read up on the warnings before you use it. (It
may not be very heat tolerant, and is not a high-strength filler, for
example.)


c) as epoxi but 1 komponent?


I don't think so. There is such a thing as pre-preg, which is a laminate
material already impregnated with a slow-curing epoxy. I've never used it,
and I don't think it is what you want, but the idea is that you create
your structure then cook it to make the epoxy cure.

d) how is epoxi lowest density achived ?


With fillers.


Morgan O.

--Mac

On Sat, 23 Oct 2004 07:00:45 GMT, Mac wrote:

On Thu, 21 Oct 2004 13:05:25 +0000, Morgan Ohlson wrote:

Epoxi is widly spread...

But, sometimes other traits are wished for. Are there any marine performance
(for wood, plastic, ,metalls) glues that (compared to epoxi) are more...

a) elastic?

Marine silicon sealant is elastic and flexible, and resists high and low
temperatures, but it is not a very good adhesive.


b) low density?

I don't think you can beat filled epoxy. Use West System ultralight
filler, for example, but read up on the warnings before you use it. (It
may not be very heat tolerant, and is not a high-strength filler, for
example.)


c) as epoxi but 1 komponent?


I don't think so. There is such a thing as pre-preg, which is a laminate
material already impregnated with a slow-curing epoxy. I've never used it,
and I don't think it is what you want, but the idea is that you create
your structure then cook it to make the epoxy cure.

d) how is epoxi lowest density achived ?


With fillers.

I saw somewhere a filler namned "fairydust"... is that plastic ballons?
....are they liter compared to glass ballons?

Morgan O.