post curing epoxy laminate

[gary1]

Morning,
I'm just chasing some info on post curing epoxy to be used on a boat I'am building using the stich n glue method of construction.
(1) First up is it advisable to try and do and are there any real benifits in doing this when using Epoxy as the only information I have been able to find on post curing involves boats made in moulds.
(2) What temperature does it have to be brought up to to get the maxium benifits from.
(3) Does the post cure take place after the epoxy has been allowed to to cure naturally, or is it part of the curing process once the laminate job has been done
(4) When the ideal temp is reached post cure does it have to be maintained for any length of time before being allowed to cool
(5) Do you have to bring it back to the normal air temp quickly or can you just switch of what ever heating systen you are using and just let it cool down naturally.
I realise that all epoxies are different, but is there a general rule of thumb which applies to the questions I have asked above when it comes to doing a post cure on epoxy
Any help or advice on this would be greatly appreciated
Thank's
Gary

[JRL]

Originally Posted by gary1

Morning,
I'm just chasing some info on post curing epoxy to be used on a boat I'am building using the stich n glue method of construction.
(1) First up is it advisable to try and do and are there any real benifits in doing this when using Epoxy as the only information I have been able to find on post curing involves boats made in moulds.
(2) What temperature does it have to be brought up to to get the maxium benifits from.
(3) Does the post cure take place after the epoxy has been allowed to to cure naturally, or is it part of the curing process once the laminate job has been done
(4) When the ideal temp is reached post cure does it have to be maintained for any length of time before being allowed to cool
(5) Do you have to bring it back to the normal air temp quickly or can you just switch of what ever heating systen you are using and just let it cool down naturally.
I realise that all epoxies are different, but is there a general rule of thumb which applies to the questions I have asked above when it comes to doing a post cure on epoxy
Any help or advice on this would be greatly appreciated
Thank's
Gary

1. Post curing is a necessity for high temperature range epoxy's. Like those that will be near 200 degree or higher temps. Most of your off the shelf stuff will never need to be post cured.

2. Each manufacturer will give you the exact temp/time to post cure its epoxy. There is no universal post curing temp/time.

3. Post curing happens "post cure". You let it cure, then place it in the oven using the manufacurers specs. Some resins will not cure at room temp. They are heated immediately affter the layup to a temp just below the cure temp. This lowers its viscosity and allows air/volitiles to escape more efficiently. Then once the tech is satisfied that the air/volitiles has escaped the temp is bumped up to the cure temp. Most of these resins are used in pre-preg.

4/5. Yep. Ive seen post cures as long as 12 hours. As short as 2. All at a maintained temp. Thats with controlled ramp up and downs of the temp as to not heat or cool the part to fast.

Post curing maximizes the potential of whatever brand epoxy you will use. The question is whether the performance gain is worth your time.....because sometime the gain is really small.

[PAR]

If you're building a typical stitch and glue design, then you have no need for post cured epoxy techniques.

[gary1]

Evening JRL & PAR,
Thank you both for your'e advice, I never realised it was such a technical procedure. After I have finished laminating I think will just leave the lights on in my shed shut the door and come back in a couple of days after letting it cure out on it's own. Thats about as technical as I want to really get. Once again thank's for the help I appreciate it
Stay Safe
Gary