Heating hysol

[Wiley]

We just used a craft heat gun we found laying around the house. Definitely not a very expensive or high tech piece of equipment. Worked like a champ when we needed to move a couple ribs in the tail feathers.

[Dave Holl]

I used a cheap black and decker heat gun and a plastic scraper which I used to prise open the glued joint. I used the minimum of heat possible and peeled the joint apart.

[Esser]

I need to move a rib that is hysoled but not very far, can i heat the hysol move it and let it sit where it was? or do i need to remove all the heated hysol and reapply.

[jimcarriere]

Esser, the short answer is you'll need to reapply new Hysol if you move the rib- it just won't stick the same way it first did. I would also make a reasonable effort to remove as much of the old stuff as I could without damaging the rib or scratching the spar.

The "book answer" is that heating the Hysol enough to soften it will also permanently weaken the Hysol. That's the big difference between a thermoplastic, and a thermosetting plastic. The former (ie. nylon, acrylic, PVC) can repeatedly melt and solidify. The latter (epoxy falls in this category) are formed by curing when they are first made. Once they are cured, melting will normally damage them for good deep down at the molecular level.

The data sheet for Hysol 9460 (should be in your build manual) says that this happens at 68°C/155°F... hotter than that and the stuff gets even easier to remove. As others have noted, a heat gun makes quick work of things any time the need arises to fix one of those little mistakes

[Esser]

Thanks Jim, when I put the speed tail ribs in I had the plane on its side and three of them slowly slid down as it cured so I guess I have a big job on my hands.