CA glue---all the same?

[Marc Lanthier (Piano Lanco)]

CA (cyanoacrylate) glue is basically made of two products: ethyl
cyanoacrylate and polymethylmethacrylate. Their ratios, in the final
product, determine their degree of polymerization and also their
viscosities. CA glues react to moisture ie. that's how it sets. The vapors
of these 2 chemicals are extermely irritating to the airways. If you do not
turn you head aways form the fumes as a reflex, most likely the glue has
begun to polymerize and its "active" ingredients are depleted accordingly.
 
There are many "recipes" to super glues. The trick is to find the correct
viscosity (for pinblocks: as thin as it comes which is about 2 centipoise -
water is 1 cps). Also you have to make sure it hasn't been sitting on the
shelf for months - fresher is better. Polymerisation is slowed by cooling
but its viscosity will increase - so store in a fridge and warm to room temp
before use.
 
You might think that dissolving the glue in a solvent (such as acetone) to
reduce its viscosity and make it creep more is a solution - but beware that
most solvents that are appropriate to dilute such a polar mixture are also
very prone to absorb water - which promotes its curing (acetone might have
as mush as 10 % water content).
 
So I suggest to try to find a supplier which has a high turn around. To do
this, you might want to note the lot number on the package and go back a few
weeks later to see if it's still the same lot on the shelf. Also, buy as
small containers as possible because as soon as you break open the spout,
you will introduce moisture - tenfold more if you transfer it to a
hypo-oiler - so use quickly.
 
To say to buy a specific brand, in my opinion, is misleading since it could
be a great product if used fresh but could have been sitting on the
distributor's shelf for 6 months or more.
 
That's all that I have to say about CA adhesives for now,
 
 
Thanks,
 
Marc Lanthier
Piano Lanco
514-770-7438
1-877-PIANO10
info at pianolanco.com
www.pianolanco.com 
 
  _____  

From: pianotech-bounces at ptg.org [mailto:pianotech-bounces at ptg.org] On Behalf
Of Tom Sivak
Sent: August 2, 2007 9:25 PM
To: Pianotech List
Subject: Re: CA glue---all the same?


I didn't think it was a thickness problem.  It appears to the eye to be as
watery as the ultra-thin stuff.  Maybe the difference between thin and
ultra-thin is enough to make it work or not?
 
But pinblock plugs?  On a 75 year old Starck spinet?  
 
I guess my question might really be: are there different strengths of CA
glue?  Different formulae?  Or is CA glue just CA glue, period?  (Thickness
or thinness aside)

Tom

John Ross <jrpiano at win.eastlink.ca> wrote:

The Loctite might be thicker, therefore unable to travel.
A hobby shop usually has a fast turn over. so it should be fresh stuff. Be
sure and get the ultra-thin stuff, and get the super fine tips they have
that fit on the bottle, usually in packs of 5.
Wear a respirator if it bothers you, and get lots of ventilation in the
area.
I have never had the c/a glue fail me.
The only place I can see where it wouldn't work, would be on a split, or
separated pinblock.
In that case, if it were only a few, I would try pinblock plugs. They are
available from Webb Phillips, in two sizes.
John M. Ross
Windsor, Nova Scotia, Canada
jrpiano at win.eastlink.ca

----- Original Message ----- 
From: Tom  <mailto:tvaktvak at sbcglobal.net> Sivak 
To: pianotech <mailto:pianotech at ptg.org>  
Sent: Thursday, August 02, 2007 9:02 PM
Subject: CA glue---all the same?

List
 
Is there any difference in the quality of various brands of CA glue?   
 
I have been using Lock-Tite Super Glue, and whereas it seems to work fine
for various repairs, I have had a couple of pinblock treatments that didn't
take.  I used A LOT of it, too.  It seems as thin a viscosity as the glue
available from Schaff or the local hobby shop, so I don't think that is the
problem.  I've been buying it because it's available at the hardware store
down the street, and I like that it comes in such small bottles.  
 
But I've noticed that my eyes don't water when I use it.  Today I bought a
different brand of CA from the hobby shop, and man! I had to leave the area
for awhile, it was so gaseously toxic!
 
I had initially thought that the last two pinblocks were just too far gone
and that the glue couldn't make an impact.  Now, I'm starting to think that
the Lock-Tite glue might be weaker.
 
Any thoughts?  

Thanks,
Tom Sivak
Chicago


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