Hi everybody
I have always bonded the honeycomb in one step on the wet layup for watersport gadgets.
I am very appealed to use resin infusion, this time in an aircraft.
The alternative would be infusing the outer skin and curing it and then in a second step bonding the honeycomb to the outer skin.
Would the two step process be much heavier?
Would appreciate any comments.
Honeycomb is hard to work is unless you do it right! It requires a good film of adhesive between the face sheets to grip onto the cell walls. Doing a 2-3 cure cycle with film adhesive is one way to go. In prepreg, it’s normally curing one face sheet, adding film adhesive (or one more layer of prepreg), the core, and curing again. You then add the other face sheet with film adhesive, in one or 2 more cures. This way the surfaces don’t get sucked into the cells, and you have good adhesion. VARTM is almost impossible, unless you skin the honeycomb first, because the resin will suck into all the cells. Wet layup should work, but might still have extra resin in the cells.
Thanks for the advice.
Could you recommend a film adhesive that cures at about 80º Celsius?
In case I cure the face skin and afterwards i simply brush epoxy on the skin for adhesion of the honeycomb should I thicken the epoxy or use some special epoxy?
Splitting the process into several stteps is something I dont mind. what I dislike is a heavy wet layup of 6 square meters (awful lot of stress…)