CA Glue - All The Same??

[Jim Eller]

Is all CA glue the same if you buy it at a ww store, big box store, on-line, HF, ...?

It seems that when I purchase an expensive small bottles of the stuff in thin and thick it goes bad before I use most of it. It seems to thicken over time??

All I use it for is securing knots, small repairs, etc.

Thanks,
Jim

[Tony Bilello]

Is all CA glue the same if you buy it at a ww store, big box store, on-line, HF, ...?.....Jim

I seriously doubt it. I think of CA glue as a potential danger just like pest control chemicals. If you want the good stuff for bugs you have to go to an agricultural store. If you want the good CA glue, go to a woodworking store or a hobby shop. I think the theory behind that is that more knowledgable go to specific places where customers are assumed to be more responsible. The general public goes to Walmart and the BORGs. The stuff there is safer. I remember when little kids were gluing their fingers and eyelids shut with "Super Glue". Parents thought it was safe because it came from Walmart.

[Jim McFarland]

I use a lot of the medium viscosity finishing pens and buy it here:
http://woodenwonderstx.com/ZC_WoodenWonders/index.php?main_page=index&cPath=1&zenid=16a3a920dd13a1155fa83a4db422a742

For small amounts, I've used the Titebond brand from Woodcraft and happy with it. IIRC, Lowe's has the Titebond CA glue, too.

[Peter Quinn]

Far as I can tell, not much different. I've even used the liquid bandage from the medicine cabinet at work in a pinch. The wood working stores do offer a variety of specific viscosities and open times tailored to wood working needs which can be pretty handy for certain applications, but I'm not convinced they are "stronger", more "pure" or in any way better. For general fastening of small objects I find little difference between crazy glue and crazy expensive glue.

Think about oil for sharpening stones. A pint can of Norton stone oil in most wood working stores is approaching $10. It is mineral oil, and nothing else. A bottle of "mineral oil" for counter tops in the finishing department is equally expensive. Maybe they put a little spritz of lemon oil in there to keep things smelling fresh? Good finishes are expensive right? Well, 100% pure food grade mineral oil from my local pharmacy is about $1.85 for 1/2 gallon in the "LAXATIVE" aisle. I wonder why? Perhaps I should bring some to my local woodcraft, because clearly their mineral oil prices are full of........markup?

I have fond a number of similar strange markups at wood working stores, and I find they are often not the cheapest place to buy certain things, for other things they are the only and or best place to buy them. Care to discuss the price of acid brushes in these places?

[Andrew Joiner]

I totally agree with Peter. I get a good laugh when I look up the material safety data sheet (MSDS) on some of the pricey stuff marketed to woodworkers.

I've learned to test glues,finishes and any product that's new to my process. I find that cheap and generic is many times no different than expensive products. I don't use CA glue much,but the generic super glue I have in tiny .07oz tubes holds and is still good. I bought it 11/2088, $1 for 6 tubes.

[John Coloccia]

CA goes bad. If a staff that's not knowledgable lets stuff bake in a box in the back room for a month, and then doesn't rotate their stock, you could well just be getting old glue. If you go somewhere like Woodcraft, many will take pains to do things like rotate glues and finishes (i.e. put the new stock at the back of the back) so that you don't end up with one can that's 10 years old. I don't think most places do that unless that's their specialty.

re: purity
There are definite differences between CA glues. It refers to a family of chemicals. Saying "CA" is like saying "epoxy".

re: expense
Part of what you're paying for with "expensive" mineral oil is small quantities in convenient containers. 1/2 gallon of mineral oil to me is worthless until I've bought smaller containers to dispense it, and transferred it. You're also paying for the generally knowledgable staff. Go to the pharmacy and ask them how to remove a water mark from their coffee table, and see how many pharmacists suggest mineral oil.

[Chip Lindley]

Is all CA glue the same if you buy it at a ww store, big box store, on-line, HF, ...?

It seems that when I purchase an expensive small bottles of the stuff in thin and thick it goes bad before I use most of it. It seems to thicken over time??

All I use it for is securing knots, small repairs, etc.

Thanks,
Jim

Keep your Super Glue in the freezer between uses. Seal it in a Zip-Loc bag. It will be usable any time you need it.

[ian maybury]

I'm not a chemist, but did work for some years on adhesives development projects for a well known CA manufacturer - not recently enough though to know what the current state of play is between makes and types.

Some quite basic differences can arise between makes and types though. Most are ethyl cyanoacrylate monomer based, but there are several other monomers used in specialist applications too because they have slightly different properties. (e.g. medical grades are often the less allergenic butyl monomer) In practice most of the types we use are ethyl cyanoacrylate as far as I can remember.

Fumed silica powder is used to tune the viscosity for differing uses (water like to gel consistencies), powdered elastomers can give some limited degree of flexibility, and modifications to the cure chemistry (so called surface insensitive grades) make possible curing on slightly acidic surfaces (like on paper and some woods) where standard grades won't cure without an accelerator.

The monomer normally cures in the presence of moisture - a source of anions if I remember correctly. The stuff is stabilised in the bottle by adjustment of the PH. (addition of more or less acid) This also speeds or slows the cure on a given surface - the cure kicks off once the PH tips to become very slightly basic. Surface insensitive types are basically doped to see the surface being bonded as being less acidic than it actually is. Activators are usually mild solvents like heptane, the solvent action of which creates a supply of anions, and hence drives the cure. There are now light curing varieties as well.

In the practical sense the differences between high quality and low quality grades tends to be mostly about purity of the monomer, fine tuning of the cure system, the accuracy with which the acidity of the adhesive is set during formulation, and moisture or any other sources of contamination. Because the faster/less surface sensitive grades are less acidic and hence less stable they live more dangerously. i.e. much closer to being unstable/curing spontaneously. Meaning that to obtain decent shelf life the manufacturer must use higher purity/cleaner materials and more accurately controlled formulations.

i.e. Cheaper grades using less pure monomers, less accurately controlled formulation, and less rigorously clean packaging tend in order to get the required shelf life to either end up over stabilised (and hence slow curing/unable to sure without activator on more acidic surfaces) or prone to instability which manifests as thickening or stringing in the bottle. It's not that uncommon either to see some variation between batches of the same grade from the same maker - it's hard to avoid getting caught by contamination from time to time. (e.g. a packaging manufacturer changes a blow moulding process, but says nothing)

We're often not that bothered about the exact cure speed or viscosity in woodworking to the level that tends to be the case in low cycle time automated manufacturing applications, and we often use activators because e.g. different wood species vary so much in acidity/PH that a given CA will cure on some woods, but not on others. But we want it cheap because we tend to use quite large volumes.

So if I had to guess we probably tend in woodworking to get lower quality and less precisely formulated material. Which for most of us doesn't matter or become a big deal unless the specific bottle is unstable enough to prematurely thicken or cure before we use it up. But the risk of getting a less stable batch is probably quite a bit higher than with the high performance industrial grades produced by the high end makers.

The other big factor as already mentioned above is storage conditions. The polyethylene typically used for bottles is moisture porous (it allows a slow ingress of water which de-stabilises the contents), so the humidity of the surrounding air matters. (the dryer the better) The other factor as also mentioned is temperature - chilling slows down the degradation.

CA no matter how good (unless it's heavily over stabilised - probably to the point of needing activator on most surfaces) must inevitably have not just a finite shelf life but also probably a somewhat variable one...

ian

[Neal Daughtry]

Keep your Super Glue in the freezer between uses. Seal it in a Zip-Loc bag. It will be usable any time you need it.
Useable after you thaw it out. I keep mine in the fridge and it seems to extend the life. Might have to try the freezer trick though. Have a friend who builds RC models and he says "throw it away after 1 year".

[Jim Eller]

WOW!! Thanks to everyone for all the great info.

Ian - You may not be a chemist but after reading your reply you have me fooled. :):D:)

[Chip Lindley]

Keep your Super Glue in the freezer between uses. Seal it in a Zip-Loc bag. It will be usable any time you need it.


Useable after you thaw it out. I keep mine in the fridge and it seems to extend the life. Might have to try the freezer trick though. Have a friend who builds RC models and he says "throw it away after 1 year".

Au Contrare Neal. Super Glue straight from the freezer can be used immediately. It does not freeze solid; perhaps only thickens a bit. And, that only lasts for a minute.

[Tom Walz]

Dear ian maybury:

Now that is an answer. A big part of why I love this site is answers like that.

Tom

[Peter Quinn]

CA goes bad. If a staff that's not knowledgable lets stuff bake in a box in the back room for a month, and then doesn't rotate their stock, you could well just be getting old glue. If you go somewhere like Woodcraft, many will take pains to do things like rotate glues and finishes (i.e. put the new stock at the back of the back) so that you don't end up with one can that's 10 years old. I don't think most places do that unless that's their specialty.

re: purity
There are definite differences between CA glues. It refers to a family of chemicals. Saying "CA" is like saying "epoxy".

re: expense
Part of what you're paying for with "expensive" mineral oil is small quantities in convenient containers. 1/2 gallon of mineral oil to me is worthless until I've bought smaller containers to dispense it, and transferred it. You're also paying for the generally knowledgable staff. Go to the pharmacy and ask them how to remove a water mark from their coffee table, and see how many pharmacists suggest mineral oil.

I agree John, that most local pharmacists will know more about remedies for stretch marks then water marks, but as far as bottles to dispense mineral oil, there they have you covered! My CVS sells in the hair coloring aisle these little bottles for permanents and frosting hair with caps and very fine tips that can be cut to change delivery rate from drops to gushing, I think they are marked clairol? Some of the best little squeeze bottles I have used and cheap too!

In the restaurant business we had a saying. "Do you know what the difference between a pizza and a stone pie is? About $4."

[Dan Hintz]

Excellent answer, Ian...

[glenn bradley]

Agree the term CA or super glue is like saying epoxy; many variations. Also agree that CA right out of the freezer is fine. I live in a mild temperature swing area (40* to 105*) and store my current tube, cap up in the shop without issue. Obviously keeping the nozzle clean so the cap seats well is important.

[Andrew Joiner]

In the restaurant business we had a saying. "Do you know what the difference between a pizza and a stone pie is? About $4."

I looked up the material safety data sheet on both pizza and stone pie. Your right Peter !

[ian maybury]

A belated PS on stability/shelf life of CA which came to me while using some to build a jig tonight guys - it possibly accounts for some of the variability some may see.

It's quite important not to allow contamination of a the contents of a bottle with accelerator or anything else likely to trigger the cure.

This sounds straightforward enough, but in practice actions like running the nozzle along an activator coated surface, cleaning a blocked nozzle with activator coated fingers, or even ending up with some of the stuff suspended in the atmosphere after spraying it can be enough to cause problems. As can simply the act of running the nozzle along a surface contaminated by moisture or a slightly basic material.

Problems with the nozzle curing up tend to be the most immediate manifestation of this issue. Users running semi automatic dispensing solutions in industry tend to avoid using activators if they can because it's hard to avoid dispensing needle blockages as a result. It's not going to be such an issue if you use the stuff fairly quickly because it's quite a lot less affected in volume, but even ambient exposure given the permeability of the packaging can reduce shelf life....