Difference between 1:1 and 5:1 epoxy

[jfblouin]

Does some one can give me more info about diffence between 1:1 (1 part A and 1 part B) Epoxy Glue and standard 5:1 (5 parts A and 1 part B) Epoxy Resin. The two ones have the same viscosity and accept fillers. My supplier can have the two ones from the same manufacturer but I cant have more technicals informations.

I want to laminate a keel but I have to epoxy all the boat and I already have 5:1 resin. Can I use 5:1 resin with filler and have a stiff keel?

[yokebutt]

Are you comparing regular epoxy (I'll assume Gougeon Brothers brand) with 5 minute epoxy?

Yokebutt.

[JR-Shine]

The 1/1 is diluted more than the 5/1

Different dilutents are used, some are much better than others. For example, you can get a 2/1 that has a higher tensile strength than a 5/1 with a slight post cure (4 hrs. of 140 degrees). For the most part, 1/1 ratios are used for clear coating or quick cures.

For laminating, the 5/1 will probably be better (it will also wet out better)

Joel
Boatbuildercentral.com

[jfblouin]

I'm comparing Glen-L Poly-Grip Epoxy glue 1:1 and Poly-Shield Epoxy 1:5 resin.

[wendel]

I have a mold for a 16ft dory. How much polyester and cloth will I need to build a strong hull. First time builder, any help greatly appreciated.

[JR-Shine]

Depends on how much glass you use.

[wendel]

What do you recommend in the way of glass quantity?

[JR-Shine]

Originally Posted by wendel

What do you recommend in the way of glass quantity?

Scantling specifications can be calculated by certian rules of thumb. If I were you , I would read Dave Gerr's book "Elements of Boat Strength"

[wendel]

Thank you... I am trying to get a ballpark cost of materials for the 16 ft dory?

[pjwalsh]

1:1 ratio epoxies are usually made by adding a filler material to the curing agent, nonyl phenol is very commonly used, also a mixture of nonyl phenol and poly ethylene glycol. The main advantage of this is that the cure will be insensitive to less than accurate metering of resin vs hardener. Also the filler, being a small molecular weight will reduce the viscosity of the amine curing agent which is typically quite thick. The resin used for 1:1 formulations is typically the same bisphenol-A used for 5:1 ratio formulations.

The disadvantage of 1:1 formulations is somewhat degraded strength and barrier properties, but in many cases they are perfectly adequate.