Slow E-Z poxy or alternative?


John Hartley
 

I have an area that is going to take a while to lay up so I'm looking for some slow hardener. Looks like Aircraft Spruce no longer carries E-Z poxy 87. Does anyone have a source for some -or- a way, besides cold temperature (I'm in Florida), to slow down the regular hardener to, say, 5 hour pot life and still get a reliably strong product?

Thanks, 
John


John Nate
 

MGS has a slow hardener (H340S MGS HARDENER ) that has a pot life of 6 hours.  It wets out the fiberglass cloth really well.  It's available from Aircraft Spruce.

John Nate


John Hartley
 

Thanks for the recommendation! I'll give it a go. 


David J. Gall
 

EZ-87 is still available and is the slow hardener having a 5-hour pot life. EZ-84 is no longer available, but that was a low viscosity formulation for RTM (infusion). Last I checked, MGS was not available due to supply chain issues. I suggest you try again for the EZ-87.

On Mar 24, 2022, at 1:45 PM, John Hartley via groups.io <John.hartley1@...> wrote:

Thanks for the recommendation! I'll give it a go. 


Mike Bergen
 

John, I've been meaning to reach out to you on this topic for several days but OBE. We highly recommend the MGS system or ProSet as they are a much better resin for reasons we presented several times at SNF and AirVenture. I try to steer builders away from the EZ Poxy as it has carcinogens in it. Scaled Composites got away from the rein in 1996 and went over to ProSet unless they used prepregs.

Are you going to SNF? Richard Kaczmarek and I will be volunteers in the composite workshop all week demonstrating advanced techniques and we can discuss your lamination challenge there. Curious why you need 5 hour pot life?!

Please call me to discuss further at 443.597.3720.


Sanjay
 

Mike, Any thoughts on MGS and ProSet for fuel tank sealing applications?
Sanjay

On Fri, Mar 25, 2022 at 8:26 AM Mike Bergen <dmbergen@...> wrote:
John, I've been meaning to reach out to you on this topic for several days but OBE. We highly recommend the MGS system or ProSet as they are a much better resin for reasons we presented several times at SNF and AirVenture. I try to steer builders away from the EZ Poxy as it has carcinogens in it. Scaled Composites got away from the rein in 1996 and went over to ProSet unless they used prepregs.

Are you going to SNF? Richard Kaczmarek and I will be volunteers in the composite workshop all week demonstrating advanced techniques and we can discuss your lamination challenge there. Curious why you need 5 hour pot life?!

Please call me to discuss further at 443.597.3720.


Mike Bergen
 

Sanjay, sorry for the delay in response as the last two weeks were eaten up by preps and attendance at Sun N Fun as Richard and I volunteer at the composite workshop all week and bring a lot of stuff for demos.

Epoxies are just not the best solution for fuel tanks if there is alcohol involved. Richard Kaczmarek has had great success in splashing the inside with Rhino 9700. Very hard to splash the entire inside of a Quickie fuel tank as it is not easy to toss it around. ;-)

What I have done with the inside of my Q200 tank is use Nexus veil with Derakane 470 vinyl ester resin during construction. This is the same approach that is used in fuel storage tanks. But the only way to get the vinyl ester to adhere to the bottom of the epoxy fuselage is to wet the tank area with wet epoxy, kinda wipe it so as not too wet and sprinkle cotton flox over the entire area. The next day you vacuum the loose flox leaving fibers standing on end to provide the tooth needed for the vinyl ester and Nexus to grab, otherwise the adhesion is too poor between the two different resins. This is due to the amines in the epoxy that frustrate the cure on the vinyl ester.


Robert Cringely
 


Vinylesters don’t like to stick to epoxies, that’s for sure, so I’ll offer another option. I have an all-aluminum Davis DA-2A that is the only one ever built with wing tanks. Alas the original builder didn’t know about Pro-Seal or chose not to use it so the tanks have always leaked a bit. And as you can imagine any bit is too many bits in this case. What to do?

We sloshed the tanks with Eastwood Gas Tank Sealer, specifically the type for gas with ethanol just in case. That was a year ago. The plane hasn’t yet flown because we’re doing a new panel, but the tanks are deliberately full and haven’t leaked a drop in that time. We used two gallons and by the time it all dried we’d lost less than a gallon of capacity. 

It’s just a thought…

Bob


On Wed, Apr 13, 2022 at 7:07 PM Mike Bergen <dmbergen@...> wrote:
Sanjay, sorry for the delay in response as the last two weeks were eaten up by preps and attendance at Sun N Fun as Richard and I volunteer at the composite workshop all week and bring a lot of stuff for demos.

Epoxies are just not the best solution for fuel tanks if there is alcohol involved. Richard Kaczmarek has had great success in splashing the inside with Rhino 9700. Very hard to splash the entire inside of a Quickie fuel tank as it is not easy to toss it around. ;-)

What I have done with the inside of my Q200 tank is use Nexus veil with Derakane 470 vinyl ester resin during construction. This is the same approach that is used in fuel storage tanks. But the only way to get the vinyl ester to adhere to the bottom of the epoxy fuselage is to wet the tank area with wet epoxy, kinda wipe it so as not too wet and sprinkle cotton flox over the entire area. The next day you vacuum the loose flox leaving fibers standing on end to provide the tooth needed for the vinyl ester and Nexus to grab, otherwise the adhesion is too poor between the two different resins. This is due to the amines in the epoxy that frustrate the cure on the vinyl ester.