Epoxy Brands

[bigone5500]

I have seen here on this site and others, the mention of West Systems epoxy. I have a brand called Dave Patrick's Model Magic epoxy. Has anyone else used this brand and is it comparable to West System's epoxy?

I use the 6 min and 20 min versions of Dave Patrick's Model Magic. It's a 2 part system like West's.

 

[MarkM]

ALL epoxies are 2 part. Read the directions: Do you mix equal parts of resin and hardener? If so then it's hobby grade epoxy. West and similar aerospace/marine epoxies are usually 5:1 or 3:1 parts resin:hardener. The difference in ratios is that the hobby grade epoxies add fillers, which do not contribute to additional strength, to achieve the 1:1 ratio; West and similar lack these fillers.

Most likely the stuff you have is the typical "hobby grade" epoxy and is not comparable to West Systems. That being said, hobby grade epoxies are just fine for most construction. Since you seem to be an LPR and MPR flier, I'd stick with the stuff you have. It will work just fine. West and similar is pretty expensive stuff and really only needs to be used when a lot more strength is required or when laminating tubes with carbon fiber or fiberglass. In fact, for most LPR kits you can use aliphatic (wood) glues and the rockets will be lighter than when constructed with epoxies.

 

[cjl]

No, it is not comparable. However, what you have will work fine unless you want to do work with fiberglass or carbon. I have rockets built with that that can take full I and J motors without any problems, and up to 600+mph. You're fine for almost anything with that epoxy.

 

[maxpower]

Originally posted by MarkM
ALL epoxies are 2 part. Read the directions: Do you mix equal parts of resin and hardener? If so then it's hobby grade epoxy. West and similar aerospace/marine epoxies are usually 5:1 or 3:1 parts resin:hardener. The difference in ratios is that the hobby grade epoxies add fillers, which do not contribute to additional strength, to achieve the 1:1 ratio; West and similar lack these fillers.

Most likely the stuff you have is the typical "hobby grade" epoxy and is not comparable to West Systems. That being said, hobby grade epoxies are just fine for most construction. Since you seem to be an LPR and MPR flier, I'd stick with the stuff you have. It will work just fine. West and similar is pretty expensive stuff and really only needs to be used when a lot more strength is required or when laminating tubes with carbon fiber or fiberglass. In fact, for most LPR kits you can use aliphatic (wood) glues and the rockets will be lighter than when constructed with epoxies.

1:1 means it is hobby grade? Is that true? I have some Aeropoxy that mixes 1:1 and according to tests by John Coker it is stronger than West Systems epoxy

 

[cjl]

No, it does not mean that it always will be, but generally, commercial grade laminating resins (like west) or aerospace resins (like aeropoxy and pro-set) are not mixed 1:1. My west mixes at 5:1, and my pro-set mixes at 10:3.

 

[MarkM]

Originally posted by MaxPower
1:1 means it is hobby grade? Is that true? I have some Aeropoxy that mixes 1:1 and according to tests by John Coker it is stronger than West Systems epoxy

You're probably are talking about the Aeropoxy ES6279 type (or the other type used for metal bonding). This is their structural adhesive with a paste-like consistency. And yes, it's very high quality and a 1:1 mix; one of the 'exceptions' to the 1:1. But, in general, most 1:1 mixes are the types you find in the hobby shops in the small bottles, which are loaded with non-structural fillers.

The reason the ES6279 is 1:1 is because it, too, has filler already added. However, this filler is completely different than the fillers used in hobby epoxies. This filler provides lots of extra structual integrity to the epoxy mix; it's a great alternative to using West combined with a structure filler like colloidal silica or milled fiber. It's great for general bonding and filleting, but has very little 'liquid' characteristics so if you need to pour the epoxy or laminate, Aeropoxy's PR2032 laminating epoxy is what you should use. The laminating stuff is a 3:1 ratio.

 

[MarkM]

Ignore...double post.

 

[maxpower]

Originally posted by MarkM
You're probably are talking about the Aeropoxy ES6279 type (or the other type used for metal bonding). This is their structural adhesive with a paste-like consistency. And yes, it's very high quality and a 1:1 mix; one of the 'exceptions' to the 1:1. But, in general, most 1:1 mixes are the types you find in the hobby shops in the small bottles, which are loaded with non-structural fillers.

The reason the ES6279 is 1:1 is because it, too, has filler already added. However, this filler is completely different than the fillers used in hobby epoxies. This filler provides lots of extra structual integrity to the epoxy mix; it's a great alternative to using West combined with a structure filler like colloidal silica or milled fiber. It's great for general bonding and filleting, but has very little 'liquid' characteristics so if you need to pour the epoxy or laminate, Aeropoxy's PR2032 laminating epoxy is what you should use. The laminating stuff is a 3:1 ratio.

I was referring to 6209. I have used it for laminating and I have used it making my own G10 fins. I really like the stuff but will probably get some West systems as I do more laminating.