Lotus Articles.

Body Bobbins – Removal And Rebonding New Bobbin Into Fibreglass.

The bobbins in the elan body are subject to omnidirectional forces, so it’s no surprise to discover loose bobbins that require either total removal, and perhaps replacement with a new bobbin. There are certain places where bobbins are located that are difficult to replace or rebond,  but there are also places on the elan body where replacement is quite simple to do.

Two of the easiest to replace are the bobbins that are placed at each side of the lower part of the dashboard, when the discovery (during the rebuild)  was made that the left hand bobbin was both very loose and also out of alignment with the chassis, it did not take long to decide to dig the old bobbin out and replace it with a new bobbin.

The easiest way to remove a bobbin is to drill a series of small holes through the fibreglass around the perimeter of the bobbin, then change to a larger size drill, and proceed to drill larger holes through the existing holes,  another great way, is to use a die grinder fitted with an oval shaped carbide burr, which will quickly remove all the unwanted fibreglass, as well as clean the surrounding area,  in readiness to carry out the layup of the new bobbin.

boddy bobbins

Old and new body bobbins

The old bobbin on the left has been successfully removed from the fibreglass, despite that fact that it was loose, they are still tough to remove, the drilling of holes around the bobbin plus the clean up with the carbide burr mounted in the die grinder provides a quick and easy clean up,  of course,  it’s a very messy job, but nothing that a vacuum cleaner wont take care of. Make sure to remove enough fibreglass and clean a fairly wide area so that the new fibreglass layup will create a strong bond to the original F/glass body material.

fibreglass preparation

fibreglass preparation

The original fibreglass is now cleaned up and is ready to offer up the new bobbin, a the new bobbin is clear drilled to 3/8″ and fastened to the threaded chassis hole with a suitable length UNF bolt. One small hint here, before the bobbin is set with the bolt, smear some oil onto the chassis so that the resin and layup wont stick to the metal of the chassis, but be very careful not to get oil or grease one the prepared f/glass.

Pocketed strand mat peices.

Pocketed strand mat pieces.

Prepare and pre-cut a  sufficient qty of strand mat so that everything is prepared and ready to do the layup. The diamond shapes are required to allow the glass strand mat pieces to be easily pushed over the bobbin during the repair and lay up.

Layup of new bobbin

Layup of new bobbin

The new bobbin is perfectly matched to the chassis hole. Note it is important to bolt the body to the chassis at the front and the back to ensure that all chassis mounting holes and bobbins actually align correctly, failure to do that may give you more alignment problems than you want.

Bobbin rebonding during curing

Bobbin re-bonding during curing-hot air gun to speed curing up.

During cold weather,  resin can be quite slow to cure, a hot air gun can speed things up considerably as shown here.

The completed job

The completed job

The image above shows the finished job, which only took a couple of hours to complete. this kind of fibreglass work is basic maintenance of work which most elan owners should be capable of doing, it is not rocket science by any means.

Comments

  1. Bob Withum says:

    I’ve never done a bobbin, doesn’t look hard, I have one needing fixing. Like many Elans I have issues with the drivers door, no surprise there. The bottom cup bobbin, I guess thats what its called, has enlarged thru years of use and needs replacing. No adjusting stops the door from dropping a bit when opened. Ever replaced one or have a write-up like this?
    .

  2. Hi Bob.
    Yes, I know what you saying, once the bottom bobbin cup wears, only a new cup will correct the problem. I think we have a pattern to re cast new cups, I will check that out. They are sod to rebond into the same spot, but a simple jig should help. I will get back to you.

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