Spar Attach Epoxy

[Esser]

Does the epoxy for the spar attach brackets need microballoons? The instructions don't mention it but a few people on here have said it does need them.

[BobRS]

As a rule, I used a small mount of micro-balloons in every mixture of Hysol. Ran out about 6 months ago, and purchased a container from Spruce ... I have a lifetime's worth for a few $ (USD or CDN).

I looked for a photo during the riveting, but it was pretty messy with the Hysol (w/micro balloons) squeesing out which is probably why I wasn't handling the camera. So yes, the spar attachment shown has the standard mix of Hysol + balloons.

BobRS
SS 7
N104Y

[jiott]

One of the main purposes of the balloons is to keep a small separation between the steel bracket and the aluminum spar to prevent galvanic corrosion of the dissimilar metals. All thru the Kitfox manual it says to add the balloons wherever you glue dissimilar metals.

Jim

[Jfquebec]

I put a little bit of microballons to have a good leveling bed for bracket .......but not to much thick....and don't be cheap with hysol....