What Hysol glue to choose?
Hysol glue is a great product. The cartridge system enables you to meter exactly the proper mix ratio and the tips will get you to do a professional job very easily.
However, there are basically 3 choices of glue.
1. Hysol 9462
http://www.ultimate-jets.net/collections/glues/products/hysol-9462
It is a great glue that makes very strong joints and remains slightly flexible when cured. This is perfect for gluing formers in a fuselage for example. This glue is slightly more expensive than the two other types and has a setting time of 7 hours, which is quite long and requires building planning to avoid wasting time.
It has the highest shear strength of all 3 types of glues.
2. Hysol E-20NS
http://www.ultimate-jets.net/collections/glues/products/hysol-e-20ns
This is the glue I use the most. It is very thick and never sags. It is completely white, sets quite fast and becomes very hard when cured. Fantastic product.
3. Hysol E-20HP
http://www.ultimate-jets.net/collections/glues/products/hysol-e-20hp
This is a useful type of glue as well. I use it when I need to push the glue in thin space/ holes/ cracks as it is quite fluid. This is the perfect glue for fixing hinges, repairs, retract plates reinforcing, etc...
The glue sets in about 20 minutes and is translucent. It sets very hard and has a slightly higher shear strength than E-20NS.
Note that some people have reported strong skin allergy with E-20HP.
4. Hysol 4090.
This is a chemical innovation from Henkel.
https://www.ultimate-jets.net/collections/glues/products/loctite-4090-hybrid-resin
This is a hybrid blend of CA and epoxy glue and offers the advantages of both materials.
It sets to a medium hard compound within about 3 minutes.
It can be accelerated with CA kicker for instant fixture and sets to 50% strength in 24 hours.
Once fully cured ( one week ) it has the strength of the best Hysol epoxies and very good shock resistance properties.
We use 4090 constantly on our UAV production line as it is MIl certified for our purpose and significantly reduces our assembly time, while retaining most of the strength and life span of other Hysol products.
In practice it is absolutely imperative to use proper Nitril/ Ultra nitril gloves when working with these products. One can find very nice thin Nitril gloves on the market that would not reduce your skin feel too much and protect you nicely for a certain period of time as indicated by the manufacturer. I also recommend the use of a mask with organic fumes filter when using epoxy as the vapors are quite toxic.