Mounting seats in fiberglass body

[trustno1]

Does anyone have any tips on mounting seats to a fiberglass body?
I'm a little concerned about the safety of mounting the seats directly to the body. Belts also.

Thanks, Scotty

 

[cgbexec]

Fiberglass is strong, but not very stiff. I would think that if the fiberglass body was set up correctly, it would have steel or aluminum plates laminated into it for seat mounts. If it does not, then I would purchase a roll bar/ cage that ties into the frame and has seat mounts. I am in the boat buisness and bolts easily pull out of fiberglass without laminated plates. You could use large washers, but I would not trust that. You need large laminated backing plates. My suggestion is to call the manufacturer of the body and ask them. They buit it and should be able to tell you if mounting seats to their body is DOT leagal. Good Luck.

Chris B.

 

[ken75ranger]

Double up some large flat washers and bolt them down. If you think the seats will pull out how is the body going to stay mounted? %)

 

[oh2bnok]

I ran some wide flat metal strips from side to side and larger washers. I may glass in the strips but not sure it is needed. I may also run a wire cable from the set bolts to the frame. Similar to the way the early corvette sets are secured.

 

[cgbexec]

Double up some large flat washers and bolt them down. If you think the seats will pull out how is the body going to stay mounted? %)

The body is mounted in with 8 mounts and is connected by linkages, hoses, and other various connections. The weight is spread over a very large area. In an accident, force would be applied horozontally to the fiberglass. Fiberglass is very strong across its plane. A seat however acts like a lever and would pull perpendicular to the plane of glass. This is the fiberglass' weekest link. If you could make large backing plates and connect them side to side, I think that would be fine. A strap to the frame would also be a good idea if possible. I would still call the body manufacturer and check with them.

Good Luck!

Chris B.

 

[broncow72]

It is always better to mount seats and belts to the cage. This will eliminate your delima.

 

[cgbexec]

Laminating the plates will greatly increase the strength depending on which direction the force is applied. If you take a fiberglass panel made with 3 layers, you can easily flex it. Once you bend it to a certain point, you will have a catastophic failure as the panel breaks in two. If you take a panel make with 6 layers, it will be much stiffer, but you can still flex it. Again if you flex it to its fail point, it will snap into pieces. If you take a 1/8 piece of plywood and laminate it between two layers of glass, you won't be able to flex it without a much greater amount of force. It can still fail, but it would take a much greater force to do so than glass alone. Fiberlass with a coreing material or a plate laminated between layers of glass is essentially a truss. This is much stronger than any of the materials on their own.

Chris B.

 

[eds66bronco]

metal plates with nuts welded on glassed into place works well. if you work alone it makes install/removal a snap. the kentrol tubs have a glassed in plywood core in the seat mount areas from what i remember.

 

[trustno1]

Thanks for the info. I don't know what company made the body. I bought the bronco with the body already on it. I don't know if there is any reenforcement where the front seats mount, but I know there isn't any for the rear seat. I think the body is old. I'm going to try making some laminated strips as discribed, but if anyone knows of someone that builds seat frame that I can weld to my existing roll cage, I would go that route.
Thanks, Scotty

 

[Recko555]

I second mounting the seat and seat harness to the cage.

 

[eds66bronco]

check out completeoffroad. mike offers kits for seat mounts that will weld to your cage.
http://completeoffroad.com/wsm/i-52_seat_mounts-roll_cage.html

i'm sure he could hook you up with something for the rear seat as well