Making Penetrating Epoxy?
Wadda Ketch
adding a substance to lower 'regular' epoxy's viscosity.
However, being practical, I'd like to know if it would work.
For example, could I add acetone to epoxy, and obtain a substance that
would be similar to 'off the shelf' penetrating epoxy?
If not acetone...would there be anything else?
David Carnell`
what they actually use. They obviously use stuff like toluene and some
alcohols. As the alcohols are water soluble, there might be slightly
better penetration of wet wood, though unlikely significant. Gougeon's
published research shows that cured highly diluted epoxy (proably CPES) is
no barrier to water. Any highly diluted epoxy makes a spongelike
structure after the solvent evaporates. Check out Progressive Polymers;
he has his head screwed on right about diluted epoxy.
Orinoco
warm the work and then while appling the epoxy to the work use a heat gun to
thin it down, just gently mind, this will thin the epoxy sufficiently to
penetrate the work!
"Wadda Ketch" <no_e...@none.com> wrote in message
news:g7508u4db3p2f7c0i...@4ax.com...
Jim Conlin
better. However, if the temperature of the part is raised after the epoxy is
applied, the work 'outgasses' and you get lots of bubbles. Robb White developed
the idea of heating the boat mightily, then applying the epoxy and letting teh
whole works cool. Sounds good to me. Combines warm temp for penetration with
dropping temp for no outgassing.
Wadda Ketch
At
http://www.epoxyproducts.com/penetrating4u.html
the web site for Progressive Epoxy Polymers, in part, I found....
<quote>
My Recommendations
To create what I believe would be the best available penetrating
epoxy, I would thin a good quality, low viscosity epoxy 10% with
xylene. This would improve penetration of the epoxy upon porous
surfaces. I might thin this epoxy as much as 25-33% if I was not
overly concerned about the rubbery mass that would form, or if
using it as a surface sealer (where much of the solvent will evaporate
out of the mixture before the epoxy begins to gel). Warning the epoxy
will decrease its viscosity and improve penetration. So too will
warming the surface it is being applied to. As the object cools, the
air in it will contract, helping to draw the epoxy into the object.
<end>
On Sat, 02 Mar 2002 12:13:06 GMT, David Carnell` <davec...@att.net>
wrote:
P.C.
"Jim Conlin" <con...@attbi.com> skrev i en meddelelse
news:3C819EC1...@attbi.com...
> Certainly temperature lowers the viscosity of epoxy, which helps it penetrate
> better. However, if the temperature of the part is raised after the epoxy is
> applied, the work 'outgasses' and you get lots of bubbles. Robb White
developed
> the idea of heating the boat mightily, then applying the epoxy and letting teh
> whole works cool. Sounds good to me. Combines warm temp for penetration with
> dropping temp for no outgassing.
Now It's not to make the discussion into a talk about different brands ,but I
need to point out, that the experiences I have, is with Hempel's epoxy wood
primer.
This fluid shuld be as thin as Alcohol, and I guess there are a reson for
that, ------- but my advise, if anyone want to experiment with different
thinners, are that if you try alcohol ,you must be aware that most of that stuff
for industrial use, contain up to 10 pct. water , then on the other hand ,if
this is a good thinner without the water, you can mix the spirti with some
"burned chalk" , guess you know the stuff as Ca O somthing, that will react
heavily with water, producing calcium hydroxide, removing the water from the
spirit and filtering the remains, you proberly saved quite some $.
Anyway wood are kind of "double hollow" ,in the sence, that each cell will be
able to contain some floating water, but it is not that ,that make wood change
dimensions according to being wet or dry.
And I guess that this fact, also is an important issue ,talking about wood
primers.
While when you dry wood, most of the drying process leave no results before the
water are dried out of the emty cells, and the real drying process start ; the
one that deal with bringing out the water from the wood/dry-stuff. Or in other
words, you can remove 90 pct of the water contained in the wood cells, but first
when the moisture are relesed from the cellulose that form the cells, the wood
will start to change dimensions.
Now all this is known facts, even I havn't got the figures in my head, but it
also mean, that what you shuld watch, is not if the wood again can be water
filled within the cells, but if the wood also start to change dimensions, as
then the dry-stuff have not been prepared with the epoxy wood primer.
Have a nice day.
Per Corell.
http://d1o111.dk.telia.net/~u139600113/a
Dajofa
only do this when coating something for penetration though. Would never do
this where I was bonding or laminating as I am sure it degrades the bond
strength.
Dave
Al
good point, be aware that industrial production of ethanol (alcohol)
from ethene and steam gives you an alcohol about 95% pure (the rest
being water), you need an additional process to get the purity higher...
just something to watch out for.
Al
Meindert Sprang
> > news:g7508u4db3p2f7c0i...@4ax.com...
> > > ...being a cheap sucker, I'd like to 'make' some penetrating epoxy by
> > > adding a substance to lower 'regular' epoxy's viscosity.
> > >
> > > However, being practical, I'd like to know if it would work.
> > >
> > > For example, could I add acetone to epoxy, and obtain a substance that
> > > would be similar to 'off the shelf' penetrating epoxy?
Why are you so keen on penetration of the epoxy? If you use epoxy to glue
two pieces of wood, you apply plain epoxy of both surfaces, add some
thickened epoxy to fill possible voids and push both parts together. This
will create a bond that is stronger than the wood itself.
So when you just use it as a caoting, it seems to me that the epoxy still
bonds equally well to the wood.
Meindert
Paul Oman
P.C.
"Meindert Sprang" <mhsp...@customware.nl> skrev i en meddelelse
news:3c82...@news.nb.nu...
> So when you just use it as a caoting, it seems to me that the epoxy still
> bonds equally well to the wood.
I wonder, if bond onto epoxy hardened for a month, is as strong as bond to
somthing just hardened.
P.C.
Glen Evans
> somthing just hardened.
> P.C.
No. The recently cured epoxy will still be somewhat chemically active
making a chemical bond possible whereas the old epoxy's bond will be
only a mechanical bond. However, for most applications, the
mechanical bond is more than strong enough. Almost all boat building
depends principally on mechanical bonds at its critical structural
joints.
Glen
Tucson QA 78
Bob Mifflin
Industrial Formulators, Burnaby, B.C. 1-800-778-0833 Make a product called
S1 expressly for this purpose.
Bob
Wadda Ketch <no_e...@none.com> wrote in message
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Brian Stephenson
heavier coats after the penetration coat use denatured alcohol. This is
alcohol with no water in it anlike rubbing alc which has a high water
content. I do a lot of small work(model airplanes) where we want to
saturate fiberglass,, penetrate the wood, but use a minimum of epoxy to
reduce weight. Since I use smaller amounts, I use gas line antifreeze.
Mix up a batch of resin, cut as required to reduce vis (I often reduce
to water like) and brush it on. The alc evaporates and leaves a finish
that really soaks in and grabs. Then you can apply thicker coats. No
loss in strenth should occure. I have used the heating meathod which
does work but you gotta be real fast. The heat exellerates the setup
time exponentially.....brian
Jim Conlin wrote:
>
> Certainly temperature lowers the viscosity of epoxy, which helps it penetrate
> better. However, if the temperature of the part is raised after the epoxy is
> applied, the work 'outgasses' and you get lots of bubbles. Robb White developed
> the idea of heating the boat mightily, then applying the epoxy and letting teh
> whole works cool. Sounds good to me. Combines warm temp for penetration with
> dropping temp for no outgassing.
Joe Kovacs
>If you are using this as a sort of primer coat to be followed up by
>heavier coats after the penetration coat use denatured alcohol. This is
>alcohol with no water in it anlike rubbing alc which has a high water
>content.
:-) Not so. 'Denatured alcohol' has nothing to do with water
content, it may or may not have water with it.
Chemically, the alcohols go methyl, ethyl, propyl, butyl,
pentyl...alcohol. Methyl is the lightest.
Ethyl alcohol is drinking alcohol, like in beer or vodka. It's
very inexpensive to produce, about 15 cents/gallon industrially,
In that form, liquor, it's taxed very heavily and is expensive
for that.
The other alcohols, methyl and propyl alchohol and the rest are
poisonous.
Ethyl alcohol has many uses other than liquor, and it's practice
to supply it in the normal way untaxed for all these. Then
its price is based on manufacturing costs of 15 cents/gallon.
Then, however, to prevent it being drunk as liquor, it's made
poisonous, that is, denatured. Denatured alcohol is ethyl
alcohol that's been made poisonous.
There are about 80 ways to denature ethyl alcohol, depending on
the intended use. The common basic denatured alcohol simply has
about 20% methyl added to the ethyl.
When you want alcohol with no water in it, you ask for anydrous
alcohol. Or 'methyl alcohol with no water in it'. I think the
denatured alcohol sold for thinning shellac in hardware stores is
anhydrous, and says so in the fine print on the label. So if
you're so inclined, you can use that to thin epoxy.
Rubbing alcohol is generally propyl alcohol. Again, 'rubbing'
has nothing to do with water content, it may or may not have
water, it'll say on the label.
--
Joe Kovacs
Port Colborne Ontario Canada
Brian Whatcott
Concise, comprehensive, authoritative.
Brian W
On Mon, 25 Mar 2002 06:29:11 GMT, j...@wuhal.mail.net (Joe Kovacs)
wrote:
Brian Whatcott
Altus, OK
Eureka!
Hydrolyse guru
Hai, ask HYAB for the penetrating epoxy from malmgren
regards, wim
"Joe Kovacs" <j...@wuhal.mail.net> schreef in bericht
news:Xszn8.4466$je5....@nnrp1.uunet.ca...
Gordon Couger
"Joe Kovacs" <j...@wuhal.mail.net> wrote in message news:Xszn8.4466
<snip>
> Ethyl alcohol is drinking alcohol, like in beer or vodka. It's
> very inexpensive to produce, about 15 cents/gallon industrially,
> In that form, liquor, it's taxed very heavily and is expensive
> for that.
Actual cost of production of ethyl alcohol is well over $2.00 a gallon. At
15 cents we would be buring it insted of gasoline.
--
Gordon
Gordon Couger
Stillwater, OK
www.couger.com/gcouger