Can anyone suggest the product that is used for bonding the door skin to the fiberglass door panel? I suspect that it would have to be a product that has a slow curing properties.
They're normally riveted, not bonded. If you bond it, make sure you have the fit right because you won't change it when the glue hardens! Jim
I used aircraft strutural adhesive by 3M called Scotch weld on a cessna 172 project (but not my Helio) I asked what Boeing used on their jets. I fitted everything using clecos with holes for flush rivets on corners and curves instead of trying to clamp things together I had a rivet about every 4 to 6 inches. I put the glue on then rivited everything together. That project was aluminum to aluminum. Boeing uses it to glue their floors in with it. On another project where I was gluing fabric to fiberglas it kept coming apart using contact cement. Can't remember what kind it was. So I used a contact cement glue the Caterpillar co. makes called "Attach Glue" I think they glue windshields in with it. And I glued in my door seals on the Helio with 3M door seal adhesive from the automotive store.
Personally I really think you could put all the skins on a Helio at least around the cage with 3M Scotch weld and eliminate all the rivet lines. I would still use flush rivets at the corners.
I just remembered I think that was the same glue I used to attach the Sportsman Stol leading edge to my 172.
As Jim M. has posted the normal procedure is to rivet the royalite or fiberglass to the aluminum structure.
The issue is that once bonded, it is what it is.
I made a fiberglass mold for the doors, however, I used the doors off a wrecked H-800 for my H-295. It took Jim a number of hours to get the doors to fit properly.
You can can use heat to take aluminum bonded to aluminum apart I used a heat gun designed to weld plastic, a propane torch would probably work too, you have to work quickly to keep from warping things, probably wouldn't work on fiberglas to aluminum
OK. Just to note.
When I took the aluminum skin off the pilot's door to repair the fiberglass, it was riveted and bonded with a brown/red compound around the entire perimeter of the door, around the window and also across the fiberglass doubler that runs the width of the door.
It is my understanding then, that there should be no bonding compound used in conjunction with the rivets.
When I took Royalite off my H-295 doors they were just riveted to the aluminum door frame. There was no mastik, glue or anything else attached.
I kept the original covering and will look at it when I get to the hangar on Friday.
I don't know if it makes any difference, but I have the 1200 series doors.
Before I attempt to source out some compound to bond the inner door skin (fiberglass) to the outer skin (aluminum) on the left front door.
Jim Metzler - is it my understanding that on the 1200 series door, they are only riveted?
When I remove the rivets the aluminum was laminated to the fiberglass around the entire edge of the door, around the window, through the center fiberglass doubler.
Sorry to beat up an old post...just want to verify before riveting the skin back on.
I certainly haven't seen all Helio doors, but any I have had apart have only been riveted. I looked at the Helio drawing for the doors to see if there was an engineering order that bonded skins but didn't find any. I would just rivet it as that gives you more repair options down the road. Jim