Re: Corn or wheat flour as epoxy thickener for gluing?
While any sensible flour might work, that flour may also be sub-optimal.
What properties do you seek when you put in an additive?
Sheer bulk?
Then crushed limestone (agricultural lime, "that stuff they use to make
baselines", c'est tout la meme chose) is what you seek. Do not,
however, expect much luck sanding the stuff. You may also use talc in
the same way. And yes, you may substitute "baby powder" which is talc
with added fragrance. Parents are moving away from baby poweder because
inhaling it is Not Good (also true of all additives described below).
Sandability?
Then phenolic microballoons or hollow glass microspheres, are best. They
add plenty of volume (and thus are inexpensive, because they displace
the epoxy resin [expensive] while still serving as glue or filler. Great
for fairing.
Thickening agent--to make it stay put?
Then fumed silica (cab-o-siol, AEROSIL, West 406 Colloidal Silica) is
what you want. It's light, and excellent thickener, it has good light
deflection properties, and it's cheap too, per unit of volume or weight.
Wood flour, wheat flour--they do not work anywhere near as well.
Short but sweet:
http://en.wikipedia.org/wiki/Fumed_silica
Gluing strength?
Then milled glass fibers or chopped strand glass fibers, (aka "cat
hair") are what you seek.
So, what should you use? If you're lazy, use whatever's handy from the
list above, and don't worry about your ultimate finish. If you built it
right, then the drop in adhesion or other strength properties will be
small enough not to matter.
Me? I find that using the better products (bought as cheaply as
possible) is the best way to go. I've seven boats under my belt, and an
8th well underway. Epoxy and its additives are what made it all possible
(given my mediocre woodworking skills). I have never experienced a
failure of gluing, bonding, or joints. I have used "substitute" fillers
in some of my boats.
But the thing is, the most costly thing to me is my time, and there's no
better substitute for phenolic or glass balloons when it comes time to
go sanding. And frankly, too much sanding and fairing drives me
crazy--it's loud, boring, and dirty, and I always end up inhaling a
little something (if only when changing out of my clothes, or cleaning
out the vacuum cleaner, etc.). So the less of this, the better (and the
more boating!).
What properties do you seek when you put in an additive?
Sheer bulk?
Then crushed limestone (agricultural lime, "that stuff they use to make
baselines", c'est tout la meme chose) is what you seek. Do not,
however, expect much luck sanding the stuff. You may also use talc in
the same way. And yes, you may substitute "baby powder" which is talc
with added fragrance. Parents are moving away from baby poweder because
inhaling it is Not Good (also true of all additives described below).
Sandability?
Then phenolic microballoons or hollow glass microspheres, are best. They
add plenty of volume (and thus are inexpensive, because they displace
the epoxy resin [expensive] while still serving as glue or filler. Great
for fairing.
Thickening agent--to make it stay put?
Then fumed silica (cab-o-siol, AEROSIL, West 406 Colloidal Silica) is
what you want. It's light, and excellent thickener, it has good light
deflection properties, and it's cheap too, per unit of volume or weight.
Wood flour, wheat flour--they do not work anywhere near as well.
Short but sweet:
http://en.wikipedia.org/wiki/Fumed_silica
Gluing strength?
Then milled glass fibers or chopped strand glass fibers, (aka "cat
hair") are what you seek.
So, what should you use? If you're lazy, use whatever's handy from the
list above, and don't worry about your ultimate finish. If you built it
right, then the drop in adhesion or other strength properties will be
small enough not to matter.
Me? I find that using the better products (bought as cheaply as
possible) is the best way to go. I've seven boats under my belt, and an
8th well underway. Epoxy and its additives are what made it all possible
(given my mediocre woodworking skills). I have never experienced a
failure of gluing, bonding, or joints. I have used "substitute" fillers
in some of my boats.
But the thing is, the most costly thing to me is my time, and there's no
better substitute for phenolic or glass balloons when it comes time to
go sanding. And frankly, too much sanding and fairing drives me
crazy--it's loud, boring, and dirty, and I always end up inhaling a
little something (if only when changing out of my clothes, or cleaning
out the vacuum cleaner, etc.). So the less of this, the better (and the
more boating!).
> I also meant to say that the corn meal may be to thick which will makeThis matches my thoughts, the biggest reason I use micro-balloon
> a rough epoxy that will not taper to a smooth edge.
>
> Sincerely,
> Gene T.
fillers is for the beneficial effect when sanding.
Dave Carnell- the very geezer I was talking about. He seems to know what he's talking about.
--- Inbolger@yahoogroups.com, "Joe Tribulato" <scsbmsjoe@...> wrote:
>
> Oh, the link:http://www.simplicityboats.com/epoxyknowhowcarnel.htm
>
> --- Inbolger@yahoogroups.com, "Joe Tribulato" <scsbmsjoe@> wrote:
> >
> > Dave Carnell suggested pulverized limestone for filler. This link is his on epoxy, including various fillers. He is a chemist and boatbuilder so I trust his opinions.
> >
> > Joe T
> >
> > --- Inbolger@yahoogroups.com, "titanicslim" <titanicslim@> wrote:
> > >
> > > There was a good piece in Boatbuilder Magazine a few years ago about the lime thing. I think he settled on the stuff they use to make baselines- gets it at the sporting goods shops.
> > >
> > > Maybe someone with a good collection of those back issues can look it up? Had some good info and test results, I believe. Anyway, it turns out to be a superior filler in most respects.
> > >
> > > Dave
> > >
> > > --- Inbolger@yahoogroups.com, c o'donnell <dadadata@> wrote:
> > > >
> > > > ANY carbohydrate flour works. So does pulverized agricultural lime,
> > > > or Diatomaceous Earth.
> > > >
> > > > On May 9, 2009, at 12:46 PM, Brian Anderson wrote:
> > > >
> >
>
Oh, the link:http://www.simplicityboats.com/epoxyknowhowcarnel.htm
--- Inbolger@yahoogroups.com, "Joe Tribulato" <scsbmsjoe@...> wrote:
>
> Dave Carnell suggested pulverized limestone for filler. This link is his on epoxy, including various fillers. He is a chemist and boatbuilder so I trust his opinions.
>
> Joe T
>
> --- Inbolger@yahoogroups.com, "titanicslim" <titanicslim@> wrote:
> >
> > There was a good piece in Boatbuilder Magazine a few years ago about the lime thing. I think he settled on the stuff they use to make baselines- gets it at the sporting goods shops.
> >
> > Maybe someone with a good collection of those back issues can look it up? Had some good info and test results, I believe. Anyway, it turns out to be a superior filler in most respects.
> >
> > Dave
> >
> > --- Inbolger@yahoogroups.com, c o'donnell <dadadata@> wrote:
> > >
> > > ANY carbohydrate flour works. So does pulverized agricultural lime,
> > > or Diatomaceous Earth.
> > >
> > > On May 9, 2009, at 12:46 PM, Brian Anderson wrote:
> > >
>
Dave Carnell suggested pulverized limestone for filler. This link is his on epoxy, including various fillers. He is a chemist and boatbuilder so I trust his opinions.
Joe T
Joe T
--- Inbolger@yahoogroups.com, "titanicslim" <titanicslim@...> wrote:
>
> There was a good piece in Boatbuilder Magazine a few years ago about the lime thing. I think he settled on the stuff they use to make baselines- gets it at the sporting goods shops.
>
> Maybe someone with a good collection of those back issues can look it up? Had some good info and test results, I believe. Anyway, it turns out to be a superior filler in most respects.
>
> Dave
>
> --- Inbolger@yahoogroups.com, c o'donnell <dadadata@> wrote:
> >
> > ANY carbohydrate flour works. So does pulverized agricultural lime,
> > or Diatomaceous Earth.
> >
> > On May 9, 2009, at 12:46 PM, Brian Anderson wrote:
> >
I also meant to say that the corn meal may be to thick which will make
a rough epoxy that will not taper to a smooth edge.
Sincerely,
Gene T.
a rough epoxy that will not taper to a smooth edge.
Sincerely,
Gene T.
On 9 May, 2009, at 12:46 PM, Brian Anderson wrote:
>
>
> So I forgot to include the wood flour in my last order of epoxy and
> was just heading out to the shop to sweep up the sawdust and sift it
> through a mesh to get something to thicken up my epoxy with, when I
> wondered if I could use just ordinary baking flour or corn meal to
> do the job.
>
> Anybody have a good idea?
>
> Cheers, Brian
>
>
>
[Non-text portions of this message have been removed]
There was a good piece in Boatbuilder Magazine a few years ago about the lime thing. I think he settled on the stuff they use to make baselines- gets it at the sporting goods shops.
Maybe someone with a good collection of those back issues can look it up? Had some good info and test results, I believe. Anyway, it turns out to be a superior filler in most respects.
Dave
Maybe someone with a good collection of those back issues can look it up? Had some good info and test results, I believe. Anyway, it turns out to be a superior filler in most respects.
Dave
--- Inbolger@yahoogroups.com, c o'donnell <dadadata@...> wrote:
>
> ANY carbohydrate flour works. So does pulverized agricultural lime,
> or Diatomaceous Earth.
>
> On May 9, 2009, at 12:46 PM, Brian Anderson wrote:
>
> >
> >
> > So I forgot to include the wood flour in my last order of epoxy and
> > was just heading out to the shop to sweep up the sawdust and sift
> > it through a mesh to get something to thicken up my epoxy with,
> > when I wondered if I could use just ordinary baking flour or corn
> > meal to do the job.
> >
> > Anybody have a good idea?
> >
> > Cheers, Brian
> >
> >
> >
>
>
>
> === craig o'donnell
> dadadata@...
> Box 232 Betterton Md 21610
>
>
>
>
>
> [Non-text portions of this message have been removed]
>
ANY carbohydrate flour works. So does pulverized agricultural lime,
or Diatomaceous Earth.
or Diatomaceous Earth.
On May 9, 2009, at 12:46 PM, Brian Anderson wrote:
>
>
> So I forgot to include the wood flour in my last order of epoxy and
> was just heading out to the shop to sweep up the sawdust and sift
> it through a mesh to get something to thicken up my epoxy with,
> when I wondered if I could use just ordinary baking flour or corn
> meal to do the job.
>
> Anybody have a good idea?
>
> Cheers, Brian
>
>
>
=== craig o'donnell
dadadata@...
Box 232 Betterton Md 21610
[Non-text portions of this message have been removed]
So I forgot to include the wood flour in my last order of epoxy and was just heading out to the shop to sweep up the sawdust and sift it through a mesh to get something to thicken up my epoxy with, when I wondered if I could use just ordinary baking flour or corn meal to do the job.
Anybody have a good idea?
Cheers, Brian
Anybody have a good idea?
Cheers, Brian