To paraphrase Vane Jones, "Knowledge is of little value until shared with others."

Tuesday, February 24, 2015

Additional Comments Regarding CA and Other Adhesives

Although I normally do not recommend Wikipedia articles, but it does have a nice article on adhesives.  The sections starting with "Mechanisms of Adhesion" and following are very interesting and explain not only how adhesives work but how they fail. This is very important for the modeler to understand why the "glue" didn't work.

I'm more of an inorganic chemist and not into the chemistry of adhesives. I can say CA does not form a chemical bond with many substances modelers use. This leaves the 3 other potential bonding methods.

From experience CA seams to be less effective the smoother or non-porous one or both of the items to be "glued together" are.

Another comment regarding the use of CA adhesives. For that matter any adhesives. Read my post dated January 1, 2015, "Some Modeling Tips and News for the New Year Before Going Further" for other safety comments when working with CA.

Be cautious about what surface you are working on when using CA adhesives. CA will adhere to almost anything. If you have read through the posts in this blog you know I work on a 1/4" thick plate glass. The plate glass provides a smooth flat plane on which to build a model.

A couple of years ago when building something, the work which had been newly glued together with CA was left on the plate glass. In the past I've always been able to lift things glued with CA off the plate glass with a razor blade without any problems.

This time a large section of the model was stuck to the plate glass. In lifting the section, small pieces of the plate glass came along with the model!

There were pot holes in the plate glass!

After replacing the plate glass, whenever working with CA, I now place a large "ZipLock" bag or similar material over the plate glass. CA will not adhere to this material. To use the large bag, the end of the bag where the closure lock is, is cut off. Then the bag is cut with scissors along 2 edges and opened up to provide a larger area of protection for the top of the plate glass..

I tried to use material like "Saran Wrap" but could never get it smooth or to keep it from adhering to itself in a big wad.

Be careful also not to get your fingers stuck together. I have used CA for many years getting CA on my fingers. After setting, CA can be hard to remove from skin. Sometimes it has had to wear off.

Sometimes 2 or 3 fingers were stuck together momentarily. I was able to pull them apart before any damage was done. If it can happen to me, it can happen to you! Safety first!

There have been stories where individuals have glued 2 or more fingers together using CA. The fingers have had to be surgically cut apart. Be careful!

Finally, when is the CA left in the bottle no longer good to use? I use the 1/2 oz. bottle of Super Jet for almost all of the gluing required for model building.

Today I noticed there is about 1/4 of the bottle remaining. Moving the bottle from side to side the remaining CA seems to flow slower than it did when the bottle was new. This indicates to me it's time to toss the bottle out and start a new bottle of Super Jet.

Why not buy 1/4 oz. bottles of Super Jet? There are 2 reasons I don't buy the smaller bottle and finish it off. Number 1: Many times the bottle is finished-off (empty) before the CA inside starts to become thick. Number 2: Pricing - most of the cost of the bottles is the packaging cost. It's less expensive to buy the 1/2 oz. size bottle.

Each modeler has to decide for themselves which size bottle of the CA he is using, is the best for his modeling needs.

Loctite® Epoxy Plastic Bonder is an acrylic formula designed and made to bond repairs in plastic surfaces. It comes in a double syringe dispenser for equal amounts of both components to come out when required for mixing.

When mixed the 2 components react in 20-25 minutes to make "a tough, rigid, high strength bond". The acrylic material "does not shrink and is resistant to water, most common solvents and shop fluids. It has high impact resistance and can be sanded and drilled."

It is recommended for nylon and other plastics. You should check the Loctite web site for more information. All the material in quotes was taken from the Loctite web site.

I trust Loctite to have an excellent product. I am not too keen on having to mix-up an adhesive when it comes to all of the joints which have to be placed together for the Baldie kit.

If you have read over my 2 postings regarding assembling the kit, perhaps 1 batch of the Loctite acrylic adhesive could be used to glue the 2 styrene backings to each of the 2 center doors. Then another batch mixed up for the 4 backings for the 4 end doors. What I'm trying to get at is, having to mix-up batches of acrylic adhesive would add another layer of work to each of the assembly tasks.

While I like what Loctite has to offer in the way of a nylon adhesive, I'm not too sure of the actual application.

Loctite is not the only company offering a nylon adhesive. There are others. One offers a CA adhesive designed for nylon. But, we have other CA products on the market already.

Finally, at least one company has an UV activated epoxy adhesive. The material is applied to the areas to be bonded, then a small UV emitting light source is brought near material. The product is called "Bondic". You can find out more at this web site  .  I wonder how well this adhesive works?

The world of adhesives is getting more and more interesting!

Back to work of the Baldie in the next post.





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