I have read much about this on sways but still have some basic questions.
Is post curing with heat (hotbox/oven) merely a way to get a full cure quickly ? Or a requirement to get to full cure ?
Is it still benificial to a board that has a sanded hotcoat ? After several weeks ?
How about after a poly gloss coat ?
-matt
Every epoxy manufacturer I’ve dealt with recommends post curing for correct and full curing of their resins. It’s more chemistry than I know about, but the strength it would add to a surfboard would be worth a few hours in a hot box.
Beats going soft in your car on a hot sunny day.
Hi Vern.
With the epoxy I use (MGS), the compressive and tensile strength of the post cured resin goes up 2000psi. higher than non post cured resin. Well
worth the effort in my book.
Plastic bags are not the ideal way of doing it though. Un-supported boards being post cured can warp or change rocker during the heating process… It’s always best to fully support the board on a rocker table when post curing for best results…
A.P.
good advice alan
and dont overheat cuz styro has a pretty low melting temp
Thanks everyone for your replies.
I believe I now understand that post curing is a requirement. I just post cured a veneer board using the black plastic bags with the board supported by the eps block off-cut. No warping. Maybe not the best method, but will work until I build a box.
Can anyone answer weather I can post cure a couple of boards I’ve already glossed with poly ? Or do I need to sand of the gloss coat, post cure and re-gloss.
-matt
As far as I know it shouldn’t affect it.
interesting.
So, if a post cure is necessary for full compressive/tensile strength in epoxy… I can’t help but think this must apply to epoxy used for gluing structural parts. Hadn’t considered this before. If this is the case, it sounds like epoxy really is not a good candidate for gluing, for example, the frame on a wooden board. This sound right to anyone?
pat
Hi Pat.
I hope I didn’t imply it was absolutely necessary. With most epoxy systems post cure is simply optional and if chosen results in an even stronger laminate.
I have built boards with and without post curing and all have held up very well… The boards tend to post cure inside a hot van in the summer whether you want them to or not anyway…
If you want to get the most strength for your money it is simply an extra tweak worth the time and effort invested…
A.P.
Hey Vern,
PC is optional but youll get full physicals if you do.
The main benefit in surfboards is a higher heat deflection temp - the temp where the epoxy begins to loose its physicals slightly, which btw, happens to poly as well (thermoplastics soften when heated). So if youre one that likes to leave your board in your car on hot days (not recommended) then pc is for you. And yes, a little heat cures the epoxy faster too…but just a little heat is good…less is more…pc heating works best when its easy and slow…car interiors work really good out here.
Absolutely Craftee, the epoxy resin system I use (MGS) will maintain it’s full mechanical properties up to 190deg, F.when post cured…
As a matter of fact they sell a resin system (MGS 418) that will hold it’s mech. properties up to 250 to 260 deg F. after P.C. !! Talk about heat deflection temp!
I’m not a salesman, nor do I have a vested interest in MGS epoxy systems, but as a boardbuilder that has been using epoxy for over 20 years, this is some of the best I’ve ever used, especially when vacuum bagging comp. construction…
A.P.
Absolutely Craftee, the epoxy resin system I use (MGS) will maintain it’s full mechanical properties up to 190deg, F.when post cured…
As a matter of fact they sell a resin system (MGS 418) that will hold it’s mech. properties up to 250 to 260 deg F. after P.C. !! Talk about heat deflection temp!
I’m not a salesman, nor do I have a vested interest in MGS epoxy systems, but as a boardbuilder that has been using epoxy for over 20 years, this is some of the best I’ve ever used, especially when vacuum bagging comp. construction…
A.P.