Plastic Smoothing method for Fiberglass
FWIW, I used a variation on this method the other day to repair a plastic seat on an old canoe. The previous owner had lost a bolt and let the seat hang by three until a corner broke off. I was trying to think of a way to shape the (too heavy) glass I had on hand to the curve of the seat. I made an impression of the parts in a plastic bag of clay, lined it with another sacrificial grocery bag and wrapped a square of glass over the repair. Then drenched the whole thing in a batch of epoxy and folded the clay over the top of it and pressed down.
On a pretty new boat it would have been a total failure: the pieces separated a bit under the glass, there were a few air pockets, wrinkle lines from the plastic bag and some unsaturated glass on the edges. In this case it was a learning experience and matched the overall condition of the beat up canoe so well that I sanded off the nasty bits, drilled a new hole and tucked it under the gunnel with a promise to dab some white paint on it next time I had some out. The epoxy and glass are so much stronger than the original plastic that I doubt I'll have any trouble out of it.
On the plus side, the majority of the surface was very smooth. If I try something like this again, I'll separate the clay into two pieces instead of folding over and maybe superglue the parts together beforehand. Pay more attention to the cut and wetting of the glass too.
Now I'm partway through building a Teal (my first boatbuilding attempt) and considering the plastic sheeting route. A few questions for the experimenters:
* will this work with the sides already on the boat?
* Is it worth the trouble if I'm using really lightweight glass?
* How lightweight can I go with the glass cloth? I'll want some abrasion resistance on the bottom, but just enough to avoid checking on the sides. What would you pick out of this shopping list:http://www.raka.com/fibergla.htm
* How much (if any) of what kind of filler should I use with it.
Thanks,
-Brent
On a pretty new boat it would have been a total failure: the pieces separated a bit under the glass, there were a few air pockets, wrinkle lines from the plastic bag and some unsaturated glass on the edges. In this case it was a learning experience and matched the overall condition of the beat up canoe so well that I sanded off the nasty bits, drilled a new hole and tucked it under the gunnel with a promise to dab some white paint on it next time I had some out. The epoxy and glass are so much stronger than the original plastic that I doubt I'll have any trouble out of it.
On the plus side, the majority of the surface was very smooth. If I try something like this again, I'll separate the clay into two pieces instead of folding over and maybe superglue the parts together beforehand. Pay more attention to the cut and wetting of the glass too.
Now I'm partway through building a Teal (my first boatbuilding attempt) and considering the plastic sheeting route. A few questions for the experimenters:
* will this work with the sides already on the boat?
* Is it worth the trouble if I'm using really lightweight glass?
* How lightweight can I go with the glass cloth? I'll want some abrasion resistance on the bottom, but just enough to avoid checking on the sides. What would you pick out of this shopping list:http://www.raka.com/fibergla.htm
* How much (if any) of what kind of filler should I use with it.
Thanks,
-Brent