Jonker 18 meter sailplane

I have been looking at the website for this new sailplane --
http://www.jonkersailplanes.co.za/.

One photo has this caption: "The post curing oven is almost completed.
All components must be post-cured at 60°C for minimum 12 hrs for the
epoxy to achieve its LBA approved specifications."

I know that high-tech sailboats are post cured, but it was my impression
that sailplanes were not, and this was a reason that some have problems
with subsequent changes in wing shape.

Is Jonkers using a better technology that everyone else, or is
post-curing already done by other manufacturers?

Greg Arnold wrote:

Is Jonkers using a better technology that everyone else, or is
post-curing already done by other manufacturers?

All gliders that I kow of are post cured to some extent. The epoxy
resin does not reach it full potential strength untill it has been post
cured.

Robert Mudd
Moriarty, New Mexico

wrote:
Greg Arnold wrote:
Is Jonkers using a better technology that everyone else, or is
post-curing already done by other manufacturers?

All gliders that I kow of are post cured to some extent. The epoxy
resin does not reach it full potential strength untill it has been post
cured.

Robert Mudd
Moriarty, New Mexico


I see on the DG website that DG post-cures at 35 C (95 F), while Jonkers
claims to post-cure at 60 C (140C). I just looked at a book on sailboat
building, where one builder says he post-cures at anywhere from 176 F
(due to a limit in a racing rule) to 200 F.

In article , Greg Arnold
writes
wrote:
Greg Arnold wrote:
Is Jonkers using a better technology that everyone else, or is
post-curing already done by other manufacturers?

All gliders that I kow of are post cured to some extent. The epoxy
resin does not reach it full potential strength untill it has been post
cured.

Robert Mudd
Moriarty, New Mexico


I see on the DG website that DG post-cures at 35 C (95 F), while Jonkers
claims to post-cure at 60 C (140C). I just looked at a book on sailboat
building, where one builder says he post-cures at anywhere from 176 F
(due to a limit in a racing rule) to 200 F.

Gives an entirely new meaning to the expression "hot ship" doesn't it?
--
Mike Lindsay

I know that my PIK-20 was actually built in an autoclave. After 30
years, I still have no spar bump or dip. The unfortunate piece of that
is that the molds warped and the wings are a touch too thick. I believe
Sparrowhawks are cured at above 300 deg. f. if I read the info
correctly.

Jack Womack