fiberglass seat

hey i'm hopin for a few pics here or links to pics to help me understand how people are fabricating the underside of fiberglass seats.

i'll be making a cafe racer like seat for my 81 xj750, i have plenty of experience in fiberglassing surfboards and what not, so i'm not worried about that part, it's the strength i'm worried about, and how it will be secured to the frame.

I have a lot to do before i get to the seat, the seat, gas tank paint, and all that will be the last things i do, but my mind keeps thinking about it because i don't know how i will really be doing it.

thanks in advance

 

With everything stripped off your frame and out of the way, lay regular masking tape on your frame and flat pieces of cardboard between the frame rails, tape over the cardboard so the top 180* of the frame protrudes. Paint on a light coat of motor oil. Lay the fiberglass on a work surface covered with a garbage bag and wet-out, then squeegee the fiberglass there, then transfer and lay it on the prepped area. 2-3 layers, let cure, pop it off at this point to make sure it releases, clean it up a bit then - (the bottom of the pan is done, leave the tape on for now)

Spray foam from a can, from Home Repo, onto your seat pan to build-up the rear hump and the sides. Plan on a pocket for the depth of the seat cushion. After curing, shape with a bread knife and coarse sand paper, 'glass over it 3 layers. You could embed LED brake lights into your tail, causing people to just stare at your bike.

 

I think most folks just fabricate new mounts to the frame. But when I was brainstorming ideas for my 82 650max I noticed there are unused threaded brackets right next to where the shock mounts to the frame, under the grab bar, that could probably be incorporated into a fiberglass pan design easy enough.

 

:wink:

 

mounts out of what? maybe it's what i'm used to working with, but fiberglass is pretty weak, unless it has an inner structure to reinforce it, like foam, on a surfboard. will this heavy glass hold up with my weight against bars on the frame?

 

Yes, you will need something fairly substantial to support the weight on the frame. You can re-use the OEM seat pan (whole or part), create a new pan out of sheet metal or exterior plywood, or adapt a seat from a different bike. Make up the base, figure out how it will attach, then fiberglass it to make it weatherproof and add style. Not sure if there is a project here to look at, but there are many all over the Web.

 

I would use part of the original seat pan and modify it to use it as a mountable base.

 

thats what i'm looking for, I thought i'de be making a seat pan or modifying the original, but all of the info about fiberglass seat fab i've seen neglect to mention anything about it. I was under the impression they were saying to just use straight glass. I'll see what i can come up with, thankya

 

Not much fiberglass experience in general. But I've done car interior and I feel like the way we custom do doors panels, rear decks and exterior body parts is how you can do the seat(also the way I'm doing mine). This way keeps the old parts mounting points
-Take your original and strip it (on the bike take off the seat cover and cut off the old foam)

-Build up a skeleton for what you want http://vimeo.com/13475410 (this method can be done with wood, pieces of wire hangar, etc.(or you could add to and cut off some of the existing foam to get your shape)

-To build up the seat after cutting off the old foam you could use floral foam ( http://www.youtube.com/watch?v=AT6P7qaUPLw )

- Cover in fiber glass and cut off extra fiberglass

-Sand, bondo, paint/reupholster

you can customize by adding in a taillight hole or license plate holder

 

I glassed a seat laynig the glass straight on the rails. Fit beautifully, but too tight to fit upholstery between the underside of the seat pan and the rails...make sure you leave a small clearance by wrapping rails with foam or similar..