RunRyder RC
WATCH
 1 page 241 views Post Reply
11-10-2020 11:53 PM  22 days ago
Topic Vote0Post 1
helitom

rrApprentice

Pine Grove, Calif, USA

MyPosts All Forum Topic
Epoxy
For modeling purposes we have easy access to a variety of epoxies. There is - at least - 5 min, 15 min, and 30 min cure times. Does anybody know what makes that timing difference; is it the epoxy or the hardener?
The older I get, the fewer things seem worth waiting in line for.
SHARE  PM  EMAIL  HOMEPAGE  GALLERY  Attn:RR  Quote
11-11-2020 02:06 AM  22 days ago
Rojoalfa

rrKey Veteran

Punta de Mata, Monagas-Venezuela

MyPosts All Forum Topic
/
/

Well, the cure timing difference is the temperature.
The amount of hardener doesn't count on the cure time.

/
Saludos cordiales,
SHARE  PM  EMAIL  GALLERY  Attn:RR  Quote
11-11-2020 05:33 PM  21 days ago
dasd

rrVeteran

Carol Stream, IL

MyPosts All Forum Topic
I don't usually post links, but this is a great explanation to your question.
https://www.westsystem.com/instruct...poxy-chemistry/
Formerly SunFunFlyer.
SHARE  PM  EMAIL  GALLERY  Attn:RR  Quote
11-11-2020 06:01 PM  21 days ago
helitom

rrApprentice

Pine Grove, Calif, USA

MyPosts All Forum Topic
That did it.....thanks.The older I get, the fewer things seem worth waiting in line for.
SHARE  PM  EMAIL  HOMEPAGE  GALLERY  Attn:RR  Quote
11-11-2020 08:18 PM  21 days ago
ozghost1952

rrApprentice

Melbourne Australia

MyPosts All Forum Topic
Interesting topic!
I’m going to do an experiment over the weekend with 5 min and 30 min epoxy
I’ll add exact same same quantities (under same temperature)

5 min resin / 5 min hardener
5 min resin / 30 min hardener

And swap around the resin component

My gut feel is that the chemistry of the resin also plays a part / not just the hardener
Jeff
SHARE  PM  EMAIL  GALLERY  Attn:RR  Quote
11-11-2020 10:18 PM  21 days ago
Rojoalfa

rrKey Veteran

Punta de Mata, Monagas-Venezuela

MyPosts All Forum Topic
/
/

Good approach!

Most of us have a preference with epoxy brand... Like J&B...

Make tests with different hardeners... And use the epoxy of your preference...

/
Saludos cordiales,
SHARE  PM  EMAIL  GALLERY  Attn:RR  Quote
11-11-2020 10:47 PM  21 days ago
helitom

rrApprentice

Pine Grove, Calif, USA

MyPosts All Forum Topic
ozghost1952 My guy feel is that the chemistry of the resin also plays a part / not just the hardener
Jeff
This is what prompted my question in the first place. For reasons still unknown to me I ended up with a stash of various resins without a matching hardener. I was wondering if I could use those resins with the hardeners that I do have. My reading of the referenced link at least implied that curing time depended on the hardener. Please advise the results of you experiment.
The older I get, the fewer things seem worth waiting in line for.
SHARE  PM  EMAIL  HOMEPAGE  GALLERY  Attn:RR  Quote
11-14-2020 08:39 AM  19 days ago
ozghost1952

rrApprentice

Melbourne Australia

MyPosts All Forum Topic
Results are in!
I put 2 grams each of resin and hardener into small plastic cups. Temp was 23 deg Celsius
Used 5 and 30 min epoxy
R = resin
H = hardener
T = minutes (approx)

5R 5H = 5T
30R 5H = 6T
5R 30H = 12T
30R 30H = 18T

So it seems the hardener is a primary factor in setting time
Both 5 min hardener tests went close to the hardener spec. Also generated most heat and went yellow
But the resin also seems to play a part as the 5 min resin and 30 min hardener went off significantly faster than the 30 min resin and 30 min hardener

Hope thus all makes sense and the lesson for me is use like for like types if you want predictable results. I have no idea of the properties of the mixed epoxies

Jeff
SHARE  PM  EMAIL  GALLERY  Attn:RR  Quote
11-14-2020 09:07 AM  19 days ago
Rojoalfa

rrKey Veteran

Punta de Mata, Monagas-Venezuela

MyPosts All Forum Topic
ozghost1952 Hope thus all makes sense and the lesson for me is use like for like types if you want predictable results.
/
/

I see. The hardener determine the primary factor in setting time... Of course it does!

5 min hardener is for 5 min!!!

About cure time is another thing... The temperature is the principal factor.

/
Saludos cordiales,
SHARE  PM  EMAIL  GALLERY  Attn:RR  Quote
11-14-2020 03:26 PM  18 days ago
helitom

rrApprentice

Pine Grove, Calif, USA

MyPosts All Forum Topic
The important thing (to me) is that no matter what flavors of epoxy resin to hardener were mixed together, the mixture eventually cured.

Thanks for the input.
The older I get, the fewer things seem worth waiting in line for.
SHARE  PM  EMAIL  HOMEPAGE  GALLERY  Attn:RR  Quote
WATCH
 1 page 241 views Post Reply
Print TOPIC

 4  Topic Subscribe

Thursday, December 3 - 10:41 am - Copyright © 2000-2020 RunRyder   EMAILEnable Cookies

Login Here
 New Subscriptions 
 Buddies Online