Originally Posted by
speedracerntrixie
There is a difference for sure in the quality of adhesives. I am a composites tech by trade and like you I get to work with some really high end products and proprietary epoxy resin matrix systems. For my models I do not use any hobby type epoxy glues, I use a high quality epoxy laminating resin and add the appropriate fillers depending on the job at hand.
As far as CA is concerned, I used to use nothing but Zap products as it was clearly better then other brands. I initially did not like the Bob Smith brands that many hobby shops now stock as their house brand. However after a few times of having to buy the Bob Smith CA when it was the only thing available I have noticed that it seems to have been improved and it now meets my needs.
What does this mean tomthe average modeler? The answer is not a whole heck of a lot. Better adhesives means when building you can use less which will reduce cost and weight to a very small degree. Selecting the correct adhesive for the job IMO is much more important. A good example is sheeting a foam wing. I use laminating epoxy for this as well. I tape the sheets together, add a thin layer of epoxy and place the sheeting on the core, then the cores in the shucks and vacuum bag. When done the sheeting looks like it was one full sheet with no visible seams. Something that would be impossible if the sheeting was butt glued together with CA and bonded to the cores with contact cement.
Yip I agree with what you said and it is very sound logic!
There are some old school products that are exceptionally good for laminating foam cores, such as a water based latex glue which brushes on like thin milk and once it gets tacky it grips likes crazy, and in twenty years I have never seen this de-laminate. Another very good clean way of laminating foam cores is to used a watered down PVA (white wood glue) which is also brushed onto both surfaces and let to dry before positioning, then use a hot iron to iron the wood onto the foam.... the heat causes the PVA to polymerise and once again this is a permanent fix but with the added bonus of being able to reseat lifting laminate..... there are a few major advantages that both of these processes have over the two part resin compounds and they are:
1. Easy clean up with water... no acetone or keytone chemicals required
2. Low odour... can be worked inside the house.
3. quite flexible and not as brittle as polyester resin
4.not as sensitive to ambient curing temperatures.
4.no wastage as no mixing of activators, without the stress of curing deadlines.
The only downfall is that these are no good for vac-bagging.
Please keep in mind that I am a "low tech" balsa basher and have no idea how to use the high-tech compounds ...... .