Low Odor CA is a modified CA that produces very low odor and blooming. This product works great if you are sensitive to the CA fumes or are working with foam. Standard CA will attack most foam while the modified low odor M100F and M1000F CA is very foam compatible. Of course you should always test the product on a small non-visible area of your project before using any products on foam. This product, by its chemistry, is not as surface insensitive as regular Mercury CA so an accelerator like the popular Mercury MH16 may be needed. Surface insensitive simply means it will require more hydroxy ions, or water than other products. Some substrates, such as foam, have very low water content so an accelerator like Mercury MH16 is recommended. remember to test all CA products prior o using and only use small amounts for the best results.
Month: July 2015
What is the M100XF High Performance “ARF GLUE” all about?
First, to toot our own horn — This glue won BEST OF SHOW at SEFF in 2007. Yes, it’s that good!
M100XF is the result of nearly 2 years of lab work by Mercury Chemist. This work has resulted in a formulation that is among the fastest, strongest and highest quality ever available.
This product is from the Ethyl family of CA with a few proprietary additives included to increase speed and strength. M100XF is 100cps in viscosity but yet still has very good wetting out qualities when applied to a joint, it will not wick into the joint but will soak into to the joint and surrounding wood to make a very strong bond. M100XF can be used by either applying to one surface before positioning or it can be applied to the joint after the parts are positioned. With these properties M100XF is a great adhesive for using over the existing joints in ARF aircraft where a good once over is needed before the first flight.
Another strong attribute is it’s low vapor properties, while it is not a low odor product like M100F or M1000F we have noticed, during the many hours of testing, that M100XF does not produce the same amount of vapors as the standard Ethyl grade CA.
One of the best uses for this product is on poplar plywood, or as we know it Lite-ply. We have also found it to work great when sheeting with balsa or working with any tough to bond surfaces.
The reason this product works so good on the poplar plywood is due to the high alkaline content of poplar. Alkaline is a neutralizer to cyanoacrylate, which will prevent the product from reacting with the moisture in the wood; in this case an accelerator would be used to promote the curing process. The accelerator will cure the CA but with a more brittle joint, the very thing we want to avoid when gluing plywood.
Based on extensive testing this product is a great choice for assembling the ARF type models. Because of the extensive use of poplar plywood in these models most manufacturers use a PVA (polyvinalacetate) type of glue. This glue is an air-drying adhesive that cures by solvent evaporation. Simply put, when the water, that carries the adhesive to the joint, evaporates the adhesive that has spread into the joints grain and crevices dries and forms a flexible, mechanical bond. These types of products are heavy, slow and do not posses the strength of CA.
With the excellent wet-out capabilities of M100XF you can go over the joints on your new ARF and be assured the glue joints are solid. Also you can use this product during the many assembly and gluing steps required to complete the model.
Why are there different viscosities of CA?
CA comes in different viscosities so it can be used for a variety of applications. All Mercury products have the scientific viscosities rating right in the name. The thin (M5T) CA is 5 cps (cps stands for centipoises which is a scientific measurement for viscosity. 1 cps would be equivalent to water, which is a very fast wicking grade CA. To use this product you would hold the 2 pieces together and apply a small amount of adhesive at the joint, it will wick or suck into the joint and set within a couple of seconds.
The medium (M300M) is 300 cps, which is great for porous materials or anywhere you may need minor gap filling qualities. To use this product you apply it to one of the surfaces you want to glue and put the 2 pieces together and hold for about 15 seconds. This product takes 15 to 30 seconds to bond so you do have a little time for positioning.
The thick (M1100G) is 1100 cps, which is used for maximum gap filling or anytime you need working time for re-positioning or to assure a good alignment between your parts. The working time of this product is 45 to 60 seconds.
Why do CA fumes burn my nose / eyes and make my eyes water?
The fumes that you see coming from a glue joint is from the heat that is generated during the anionic polymerization process, the fumes do carry the cyanoacrylate within them, therefore when they come into contact with mucus membranes (such as the nose, throat or eyes) the cyanoacrylate reacts with the moisture contained within these areas and cause a burning sensation. This process is not harmful to the body but can be irritating; in some people it can be extremely irritating. This is not an allergic reaction although some people are sensitized to this.
To prevent problems all you need to do is make sure you move air across the work surface with a small fan. The CA vapors will dissipate very quickly into the air and become saturated within the surrounding air. If you are one of the few people that are very sensitive to the fumes you can use the low odor M100F or M1000F CA, which will not fume and cause problems.
NOTE: Some of the cheap generic/Chinese glues have toxins within them (like Benzene and Chloroform), and the fumes they create can be dangerous. Please use adequate ventilation at all times when using glue.
What is the best way to keep CA fresh?
The handling of the product, once opened, is very important to the life span of the product. Always keep the cap on when not in use, keep the nozzle clean from excess glue and contaminants, keep the CA bottle away from accelerators, and store the sealed bottle in a cool dry place.
Storing CA in the refrigerator, in an un-opened container, will keep the product fresh for a long time. Do not freeze CA; 40degrees F is an ideal temperature. Once you open the bottle do not put the bottle in and out of the refrigerator as this will introduce condensation to the inside of the bottle which will react with the CA and it will start to set up.
Some have reported that once the bottle is opened, to store it in an airtight container with rice in the bottom. The rice is a natural descant and keeps moisture out of the CA.
We at Mercury have been asked if there is a way to “thin” the CA once it hardens, or starts to harden. Unfortunately, we do not recommend trying to “refresh” a CA. Some of the other CA’s in the world will “refresh” their CA’s with toxic chemicals, like Benzene and Chloroform (yeah, like the stuff that can knock you out). This is a toxic solution (literally) and Mercury Adhesives will never recommend or condone such procedures. Do yourself, and your model a favor — just buy a new bottle.
What is Cyanoacrylate (CA) and how does it work?
Cyanoacrylate (C5H5NO2) is an acrylic resin that cures almost instantly. The only trigger, or catalyst, it requires are the hydroxyl ions in water. Since almost any substrate you may want to glue will at least have trace amounts of water on it’s surface CA will adhere to most anything.
When CA comes into contact with water it undergoes a process called anionic polymerization. In short this simply means the CA molecules start linking up into chains and these chains start whipping around to form a durable plastic mesh. The glue thickens and hardens until the thrashing molecule strands can no longer move.
2. What is the shelf life of CA?
If properly made and packaged CA can last – 2+ years (Mercury has no time frame to its warranty). The bottle that the CA is packaged in is a vital link to the shelf life of CA. Mercury Chemist have tested over 4500 different HDPE resins and there are only a handful that can properly store CA and isolate the liquid inside from the moisture in the air. The cap or closure is also very important to sealing out the water vapors that exist in the air we breathe. The Mercury bottle uses proprietary resins in the molding of the bottle and has a highly engineered triple seal closure to keep moisture out and the product fresh. This is another reason why Mercury is the only company that offers an unconditional warranty on their products.
Good to Know about Superglue
The cyanoacrylate glue, popularly referred to as superglue is one of those additions to the workbench which brought a small technological revolution in modelling. Not only did it allow to bond different materials such as metal to plastic, but also opened up the way for entirely new modelling materials such as resin. Used on plastic, it provides non-shrinking, non-destructive seams that are just great for sanding. Applied as filler, it takes scribing unlike any other.
Since there seems to be a degree of confusion about how cayanoacrylate glue works, and what it is best used for, some research was conducted and the results are presented here.
What is Superglue?
The correct chemical designation for the CA glue is ethyl 2-cyanoacrylate. An acronym ECA is also used in chemistry. There are also numerous trade names, including superglue (of course), permabond, pro grip, black max, krazy glue, cyanolite, superbonder and so on.
The actual composition of most commercial glues is typically ca. 91% ethyl 2-cyanoacrylate, 9% polymethylmethacrylate, <0.5% hydroquinone and a trace of organic sulfonic acid. Mercury Adhesives is 99.9% pure CA. Cheap Chinese CA’s can be as much as 95% CA, with 5% toxic fillers, such as Benzene and Chloroform (yeah, like the stuff you see in movies that knock people out). Some Chinese CA’s have been seen with as much as 50% filler. It is believed that these CA’s were old, and chemicals were added to thin, or “refresh” the glues to be marketable.
A common source of confusion is mixing up CA glue with thread locking glue. The main reason for this seems to be historical. In the thread locking glue, polymerisation starts in the absence of oxygene (air), while CA bonds with the aid of humidity.
How it Works
The cyanoacrylate glue hardens very quickly when trapped between two surfaces. The reaction is caused by the condensed water vapour on the surfaces (namely the hydroxyl ions in water). The water comes from the surrounding air, so obviously the air humidity is a factor that may affect bonding capabilities, or cause them to differ from application to application.
The curing reaction starts at the surface of the bonded material and develops towards the centre of the bond. Because of this, thick seams or large blobs of glue may harden less satisfactorily than surface-to-surface bonds with good fit. In a thick blob of glue, a polymerisation reaction may stop before it reaches the centre of the blob. A rule of thumb is that seams thicker than 0,25 mm should be avoided. Thick seams will also take longer time to cure.
The described relation between seam width and curing time can be used to advantage: a thick superglue-filled seam will allow adjustment of the parts, but will bond instantly and definitely when they are pressed together, so that the gap decreases below 0,25 mm. Pressing the parts harder against each other will make the glue cure instantly.
The best use for CA glues is undoubtedly attaching small details, where small amount of glue would cater for thorough polymerisation and advantage can be taken of the extremely fast bonding time.
CA glue will provide strong bonds on a wide variety of materials. The shearing and pulling resistance are very good. However, it should not be used on glass or on parts that are exposed to water.
Curing time and slow-setting inhibitors
The hardening reaction can be described like this. The cyanoacrylate is a polymer which contains its own hardener compound. However, a weak acid is added acting as an inhibitor, preventing the reaction and “holding apart” the molecules which accounts for the liquid consistency of the compound. When exposed to water, the acid is dissolved. It triggers a chain reaction and the compound cures to the solid state.
Manufacturers use the inhibitor to control the curing time of the glue. Slow-setting superglues have a larger proportion of inhibiting acid in the basic mixture.
Besides water, cyanoacrylate polymerises also in presence of alcohol and basic compounds (including weak amines). The latter can be used to produce a superglue “kicker” – a compound which triggers quick polymerisation of the glue.
Baking soda is one well-known substance with this effect. If you apply a layer of superglue to a seam and gently pour baking soda over it, the glue will cure very quickly. It makes for most effective filler for smaller jobs, and the baking soda results in a slightly rough surface which is good for sanding.
The great advantage of using superglue as filler is the total absence of shrinking which plagues most solvent-based fillers on the market.
Mercury Adhesives provides an Accelerator for our CA’s, called MH16. It is Heptane based, to produce a less violent reaction. This slower reaction is by design to reduce bubbles in the bond to ensure maximum strength. If there are bubbled in the bond, then it is weakened and may fail when under stress. Also, the slower reaction time reduces heat that can melt or damage foam.
Like water, the accelerator also affects the reaction through surface contact, so it will be much less effective on thick layers of glue. When filling larger recesses with superglue, it is therefore advisable to build up the volume in several thin layers rather than applying a large volume of glue at once.
With these precautions (i.e. working with small amounts at a time), CA can also be used for moulding smaller detail parts.
A word of health warning
Be mindful that superglue comes with its own set of health hazards.
The glue has a distinctive, strong, acid odour. Breathing cyanoacrylate fumes is irritating for your breathing organs. For some individuals, repeated or extended exposure to fumes may prompt chronic allergic reaction. In dry air (less than 50% humidity), fumes may be also be irritating to eyes, stimulating tears. With the cheaper generic/Chinese brands, the fumes can also contain toxins that can be outright harmful to your health. Mercury Adhesives are 99.9% pure CA. As such, there are fewer fumes and absolutely no toxins.
In contact with the skin, the primary risk with the CA is bonding fingers or other body parts together. This goes also for eyelids, so remember to never ever poke your hands into the eyes while working with superglue!
In skin or eye contact, CA is deemed to be non-toxic, so don’t panic, assess the situation, and seek medical help if necessary. Never try to tear the apart the bonded body parts!
It is also ascertained that CA cannot trigger allergic reactions through skin contact.