Hysol 9339

[Bruce Tuncks]

This is the epoxy you find listed for Lancairs. There might well be an alternative, but it would need to be approved.

 

Does anybody know of a source for this epoxy or approved alternative? So far, I have not been able to find an Australian supplier. I do know that several epoxies are of the same chemistry and therefore interchangeable, but you cannot assume anything here.

 

 

[spacesailor]

Just had a quick Google and "Aerospace Materials - AS9120 RevA & ISO 9001:2008 - Aviation grade materials for the Australian aerospace industry"

 

spacesailor

 

 

[Bruce Tuncks]

Thanks space, they replied to my query with "no tender": as their only comment.

 

Skyshop gave a better reply, but they don't have any as it is a "hazardous material" ,If they find an Australian source then they might come through.

 

There must be people out there who know, after all there are Lancairs being built right now I guess. Maybe they imported the stuff though while I only want a litre.

 

 

[Raytol]

Hi Bruce,

 

Try Dick Gerrard at Ironbark Composites in Melbourne.

 

03 5264 8505

 

 

[Bruce Tuncks]

I got a reply from Lancair info ( Conrad Huffstutler) who said that the current 320's use Jeffco resin. This is listed at Aircraft Spruce.

 

Conrad did not say if Jeffco is compatible with Hysol.

 

Hysol 9339 also apparently goes by the name of Loctite 3140 but the Loctite office in Australia said they don't import that line and I got the impression they were not going to on my behalf.

 

 

[Raytol]

Hi Bruce,

 

Are you using the resin to bond the shells together or lay up the tapes?

 

 

[Bruce Tuncks]

Both jobs Raytol... is there a difference?

 

 

[Raytol]

Yes and no!

 

The aircraft/ helicopter manufacturers specify different numbers but in reality it is the same resin for the bonding process with

 

fillers added, usually cotton flock "Flox" and fumed silica "Aerosil" mixed in to a shiny toothpast type consistency. The Lancair also

 

has mechanical fastening of the fuse shell joins to take any shear out of the equation. I recently used some Locktite/ Hysol on a

 

BK117 repair and paid about $800 for 900 grams! I don't think there resins are necessarily any better than other resins, as they

 

are really old technology, but they are certified by the manufacturer. The properties of epoxy resin are only optimised if they are post cured.

 

 

[Bruce Tuncks]

Thanks Raytol, I would like to use either Scheuffler resin which is used for glider repairs or Araldite LC360 which the Jabiru is made of. The Scheuffler and the LC360 are compatible with each other.

 

My guess is that either of these resins would be compatible with the Hysol stuff. I am beginning to think that it would be easier to make up a test sample by laminating a strip to an existing bit of the Lancair and then tearing it off. At least this would get around the fear of litigation which I think prevents me being told about compatible resins. This is annoying because I never want to sue anybody.

 

On the subject of post-curing, my Libelle handbook says not to worry about taking the glider to a hot country, as this will only make it stronger. I certainly had a wing-root repair post-cured.

 

 

[M61A1]

Thanks Raytol, I would like to use either Scheuffler resin which is used for glider repairs or Araldite LC360 which the Jabiru is made of. The Scheuffler and the LC360 are compatible with each other.My guess is that either of these resins would be compatible with the Hysol stuff. I am beginning to think that it would be easier to make up a test sample by laminating a strip to an existing bit of the Lancair and then tearing it off. At least this would get around the fear of litigation which I think prevents me being told about compatible resins. This is annoying because I never want to sue anybody.

On the subject of post-curing, my Libelle handbook says not to worry about taking the glider to a hot country, as this will only make it stronger. I certainly had a wing-root repair post-cured.

When you search for the adhesive, add "data sheet" to your search. Look at the Tech data sheet, It will give you a lot of information, like peel, shear and compressive strength, as well as temperature ranges and curing processes. Companies like Henkel will usually have an adhesive selection guide too.

 

 

[Raytol]

40 years of fibreglassing and I have only found one epoxy that was totally incompatible, the dreaded Rutapoxy used in the PIK 20s.

 

The Lancair is made with a pre-preg system so is totally cured and post cured before they leave the mould. Good sanding to prep

 

the glass is the key. The pre preg has a very slippery mould release system. Don't use acetone on the sanded glass! The 7781

 

type glass is ok to use in Pre preg form but is hard to wet out by hand. Either of the 275 or LC3600 would be more than enough

 

as there is no shear to worry about ( even though the rivets are drilled out the "pillars" of adhesive are left). Don't paint the wet

 

layed up areas dark colours and you should be fine. Good luck with it.

 

 

[Bruce Tuncks]

Good advice Raytol. I have never worked with a pre-preg laminate before, but I had heard that the mold-release was difficult to get rid of.

 

I know enough to use new clean sanding paper for the final sanding, and to use compressed air and an oblique light to look for shiny spots where the sanding has not reached low spots. And of course not to touch the sanded surface with greasy fingers.

 

Is there any other thing I should watch out for?

 

 

[Raytol]

Yeah Bruce, where to start!

 

Some people sand with 40# sandpaper. I think this cuts too deeply into the fibres. I use 60# white freecut paper.

 

Keep changing the paper as the mould release spreads easily with old sandpaper. Use new paper for final cuts.

 

Using the oblique light will show up shiny spots but they may have been sanded enough! 80% visible matt finish

 

is enough. You will see what I mean when you do it.

 

Make sure the glass is DRY when you laminate it! Some people even heat it gently in a heat box before use. The

 

"finish" on the glass fibres is water soluble and it is the only thing the resin sticks to ( it doesn't actually stick to the

 

fibres of glass)!

 

7781 Glass is a very tight weave so you will probably roll the resin sideways in the moulded joggle. Run a line of

 

masking tape each side of the joggle so you can clean up to the edge, outside of that I just use acetone.

 

Buy some white Vinegar and wash your hand with it after cleaning up. Reduces risk of allergic reaction.