do all (most?) epoxies bond to each other?
mx
want to use thickened to fill a gap between two loosely-fit fiberglass
parts, and some System Three laminating resin (Clear Coat, I think, I
don't have it with me right now) that I then want to use with glass
tape to reinforce over the surface of the joint. Will the epoxies
bond well to each other, if the glass is applied within a few days of
the first resin?
Also, is colloidal silica and microballons the same? I have an old
bag of house-brand microballons from Fiberlay, and colloidal silica is
recommended as a thickener. I feel like I used to know the answer to
this...but, apparently, I'm an idiot!
Thanks,
Mike
max camirand
Colloidal silica and microballoons aren't the same thing. Colloidal
silica will be harder to sand when cured. Microballoons are a lighter
filler.
As long as you give the first application of epoxy a wipe and a bit of
a sanding before you lay on the glass tape, it will bond.
-m
mx
> On Dec 8, 9:03 am, mx <wage...@yahoo.com> wrote:
>
>
> > Thanks,
> > Mike
>
> Colloidal silica and microballoons aren't the same thing. Colloidal
> silica will be harder to sand when cured. Microballoons are a lighter
> filler.
presumably microballons are hollow, so the fillet is weaker with them?
>
> As long as you give the first application of epoxy a wipe and a bit of
> a sanding before you lay on the glass tape, it will bond.
>
It's chilly here this week (Seattle) and my little garage heater is
overmatched, so after 24 hours, the first pour will probably be just
hard enough to remove the clamps, so still pretty green. I can
probably give it a solvent wipe, but not sure about sanding at that
stage.
Lew Hodgett
<wage...@yahoo.com> wrote:
> Will all epoxies bond to one another?
There are two (2) types of bonding, chemical and mechanical.
Chemical bonding occurs when a follow up layer of resin is applied
over an epoxy surface that has not totally cured.
Mechanical bonding occurs when a layer of epoxy is applied over a
totally cured epoxy surface.
You appear to be describing old work, thus mechanical bonding will
apply.
A small right angle sander with 24 grit discs will be your friend for
this job.
BTDT, forget the T-Shirt.
Good luck.
BTW, micro-balloons as a filler will do the job, especially when you
lay a piece of glass tape over it.
Lew
mx
> <wage...@yahoo.com> wrote:
> > Will all epoxies bond to one another?
>
> There are two (2) types of bonding, chemical and mechanical.
>
> Chemical bonding occurs when a follow up layer of resin is applied
> over an epoxy surface that has not totally cured.
>
> Mechanical bonding occurs when a layer of epoxy is applied over a
> totally cured epoxy surface.
>
> You appear to be describing old work, thus mechanical bonding will
> apply.
The premade glass parts are old (one is "new" but was made at least 6
months ago). Their surfaces to be bonded are fairly rough, so should
give a half-way decent mechanical bond. The glass tape is to insure
that the load is carried out over a large area of the old hull, since
its layup is not terribly thick.
But since I'm considering using 2 different epoxies for the fillet and
new cloth reinforcement, i was uncertain if they might be incompatible
in forming chemical bonds between the two new layers, or if it could
be assumed that any two common epoxies would stick to each other
chemically if the first layer is only partially cured.
Thanks,
Mike
Lew Hodgett
"mx" <wag...@yahoo.com> :
------------------------------------------
The premade glass parts are old (one is "new" but was made at least 6
months ago). Their surfaces to be bonded are fairly rough, so should
give a half-way decent mechanical bond. The glass tape is to insure
that the load is carried out over a large area of the old hull, since
its layup is not terribly thick.
But since I'm considering using 2 different epoxies for the fillet and
new cloth reinforcement, i was uncertain if they might be incompatible
in forming chemical bonds between the two new layers, or if it could
be assumed that any two common epoxies would stick to each other
chemically if the first layer is only partially cured.
---------------------------------------
Assume you get only a mechanical bond and get on with it.
SFWIW, a right angle sander with 24 grit discs is your best friend if
you are going to work with glass.
Best $100 you will ever spend, IMHO.
Lew
matt_colie
Most Epoxies blush to some extent.
If you don't sand both parts, then at least wash them well. You can
actually use a detergent and clean water rinse.
Matt Colie
Bruce In Bangkok
Essentially "epoxy" is the same stuff, no matter where it comes from.
Certainly various sellers modify their product for some specific
purpose but basically they are all epoxy. So they will stick to each
other. Sand the old layer with a coarse sanding disk, wipe with
acetone and have at it.
Cheers,
Bruce
(bruceinbangkokatgmaildotcom)
Bob La Londe
news:492c9f5e-92cc-4eba...@z35g2000prh.googlegroups.com...
There are not many things epoxy doesn't stick to.
cavelamb
Most poly-type plastics, duct tape, waxed paper, Elmer's glue, White Rain Hair
spray (PVA), etc.
Things I often use as mold release agents.
Bob La Londe
news:EtqdnZhIXuasKoLW...@earthlink.com...
I'll have to remember that hair spray one.
Paul Oman
out for amine blush. Some/most venders (like the ones you mention)
sell the bushing epoxies because they make more profit/ Blush can affect
the bond between layers.
fumed silica is a common thickener... microspheres are tiny hollow
spheres, very light and fine (comes in different densities) - thickens
the epoxy but acts like tiny ball bearings in the epoxy
paul oman - progressive epoxy polymers inc. www.epoxyproducts.com and
www.epoxyusa.com
--
I am Tosk
paul...@pauloman.com says...
Has anyone mentioned that Balloons are more for filling and fairing,
Silica is more for structural work?
SmallBoats.com
Bob La Londe
<sa...@dog.com> wrote in message
news:j6fvh5pgbpq81usjm...@4ax.com...
> And some things it doesn't really stick to at all. I have plastic
> containers I've been mixing small batches of epoxy in for years. I let
> the remaining epoxy in them cure comepletely and then hold the
> container upside down over a wastebasket and flex it. All of the epoxy
> pops right out, leaving a completely clean-as-new container.
I need some of those. I have been using plastic jars left over from other
things, and I just wind up throwing them away with each project. Been
thinking about getting some big bags of plastic beer cups for it since they
are so cheap.
I am Tosk
says...
I used to use the graduated 1 quart containers generally sold in the
paint section of Home Depot or such. Later I found them at a small resin
distributor for about .23 a piece. Use them a dozen or so times until
they crack or get too scratched up and toss 'em. easier to pour into
than beer cups, wider, and easier to work and stir in, a paint stirrer
works great...
cavelamb
> On Wed, 9 Dec 2009 09:14:01 -0700, "Bob La Londe" <nos...@nospam.no>
> quite well. Low surface energy!
>
> I also have plastic mixing blades for epoxy that you simply bend and
> the cured epoxy flakes off. They continue to come clean until they get
> scratched up.
>
> <http://www.jamestowndistributors.com/userportal/show_product.do?pid=2433&familyName=West+System+Plastic+Mixing+Sticks>
>
Ya'll mix bigger than I do!
I mix in paper bowls - and paper plates for Bondo.
These days they have a plastic coating (if any) instead of wax.
cavelamb
Micro balloons come in two flavors - Phenolic and Glass.
Glass should not be used with Polyester resin.
But either can be used with epoxy.
I believe silica is just a thickening agent to help prevent
sagging on vertical surfaces.
Cotton make a great structural additive. Milled or stranded as needed.
Or even cotton balls sometimes.
Or wood flour, if you are working with wood.
Then there are the exotic fillers.
Aluminum dust, steel powder, carbon powder, etc.
Bruce In Bangkok
wrote:
I've been using cheap plastic mixing bowls. The cheapest seem to be
the best as they are made from a flimsy, flexible, material that is
easy to remove the hardened epoxy from. I also use paper coffee cups
for small batches - throwaway containers...
Cheers,
Bruce
(bruceinbangkokatgmaildotcom)
Lew Hodgett
I bought 5 qt poly containers from a local plastic mfg house that made
them for the food industry in lots of 200 pcs.
Smaller sizes (1 OX thru 32 OZ) were plastic coated papercups
purchased in sleeves of 100 pcs from a restaurant supply house.
Paint mixing sticks from Home Depot finished the job.
A Jiffy Mixer chucked up in a drill can't be beat for larger mixing
jobs.
Lew
Wayne.B
<justwaitaf...@gmail.com> wrote:
>Has anyone mentioned that Balloons are more for filling and fairing,
>Silica is more for structural work?
I prefer micro fibers for anything structural. They are tough to sand
but very strong.
Wayne.B
wrote:
>I mix in paper bowls - and paper plates for Bondo.
I hope you're not using the bondo on a boat. I've seen some disasters
from that. Epoxy and micro baloons are *much* better for fairing.
Lew Hodgett
"Wayne.B" wrote:
> I hope you're not using the bondo on a boat. I've seen some
> disasters
> from that. Epoxy and micro baloons are *much* better for fairing.
Especially when a 30 Lb (4 cubic ft) bag of micro-balloons is less
than $25.
Lew
cavelamb
No, not for parts boat or aircraft themselves.
But I do use it for tooling.
I am Tosk
cave...@earthlink.net says...
When I was building, I used the silica for everything. I always tried to
use as little as possible to get the job done though. It is hard to sand
once finished too. When I needed more strength in a bond, I would layer
in glass fabric, or chop some glass fabric into strands and mix it in. I
don't remember ever using the balloons.
Warning, tangent below
When I was working with wood that was going to be clearcoated I would
pigment the epoxy with two colors, pine and maple, wood flower. The pine
would end up about the color of commercial peanut butter and worked for
corners on lighter wood, the maple would turn a rich brown with the
epoxy. You can also mix the two to match colors. Note, your own homemade
sawdust is not the same as wood flower, it can be used, but it is not as
smooth. I suppose the stuff your sanders save at 100 grit or smaller
might be good too.
SB
cavelamb
I had some really old West resin.
The catalyst had turned really dark.
It still worked fine, just made a beautiful darker finish.
another tangent:
I found that if you take that last coat of resin and wipe it OFF -
ALL OF IT!, just keep wiping it off (use lint free cotton rags rather
than paper towels) you can get a gorgeous satin finish.
The only downside is the danger of leaving any small puddles of
resin which will still be shiny and quite obvious.
But if you stay at it and get it clean, it makes a really pretty finish.
And way tougher than varnish.
I am Tosk
I would still cover it with UV protective clearcoat as UV breaks down
epoxy pretty quickly.
Bruce In Bangkok
wrote:
A bunch snipped
>another tangent:
>
>I found that if you take that last coat of resin and wipe it OFF -
>ALL OF IT!, just keep wiping it off (use lint free cotton rags rather
>than paper towels) you can get a gorgeous satin finish.
>
>The only downside is the danger of leaving any small puddles of
>resin which will still be shiny and quite obvious.
>
>But if you stay at it and get it clean, it makes a really pretty finish.
>And way tougher than varnish.
>
However... you really need to put some additional finish on top of
that epoxy if it is on an outside surface as bare epoxy does degrade
when exposed to UV.
Cheers,
Bruce
(bruceinbangkokatgmaildotcom)
cavelamb
sorry.
I should have added that I only use this for interior finished.
You are absolutely right.
Paul Oman
NOTE THAT 99.9% OF ANY CLEAR COAT PRODUCT HAS LITTLE OR NO UV PROTECTION
(UV BLOCKERS OR UV ABSORBERS) IN THEM.
PAUL OMAN progressive epoxy polymers inc
cavelamb
Hi Paul,
I think you could have put a line is and nobody would have yelled Spam.
After all, you were spot on target.
So - Google to the rescue...
I was impressed with all the info on the help page.
http://www.epoxyproducts.com/help.html
Might have to try some of that Basic No Blush stuff.
Richard
Paul Oman
epoxy site. 90% of the pages are info and not sales related -- paul
(merry christmas to everyone reading this!)
--
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Jean-Francois Dockes
>>> I am Tosk wrote:
>>> I believe silica is just a thickening agent to help prevent
>>> sagging on vertical surfaces.
Silica is more than a thickener, it's a thixotropic agent.
This means that the resin+silica fluid has a lower viscosity when you
stress it (ie when painting or spraying or mixing). When you leave it
alone, the viscosity will increase a lot (quickly), making it a kind of
gel which will indeed prevent sagging.
With a thickener like wood flour, the mix will still flow when set on a
non-horizontal surface (albeit more slowly). You'd have to add
unworkable (with a brush) amounts to slow down the flowing to the point
where it stays put until the epoxy cures.
The silica is kind of a miracle thickener which "knows" what it should
be doing, but, as mentioned in the thread, the end result is hard to sand.
I think it's quite usual to mix in both silica and another thickener
like micro-balloons or wood flour, to adjust the viscosity properties
and the end density and hardness to what you are doing.
jf
I am Tosk
sevres.org says...
I used combinations of silica (yes, hard to sand) and maple or pine
flour for texture and color... Maple cures about the color of chocolate,
and pine about the color of peanut butter...
--
Rowdy Mouse Racing - We race for cheese!