Quote:
Originally Posted by NeilBlanchard
Jim,
Were you the person who mentioned using Elmer's Glue on fiberglass? Would the waterproof (yellow) Elmer's work? I am concerned about several things; one is the biodegradability of the composite skin. And the very low VOC and cleanup of this glue would be much better than epoxy.
|
Hi Neil,
Yes, I mentioned the use of Elmer's Wood Glue about one year ago.
The cool thing about Elmer's is there is basically no cleanup, it's very inexpensive, no smell, and holds the glass cloth better to the substrate when wet than the West System epoxy that I have used.
The Elmer's glue does require some precautions however.
1) It's strength is about 25% less than that of West System Epoxy. I have made test samples that were 14 inches long, 2 inches thick, with one layer of 6 ounce glass on each side of the foam core. The samples were cured for one month, then tested by adding weights on top and the deflection measured with a 1 inch dial indicator.
2) The Elmer's glue needs to be sealed from the elements. This should be easy to do, but chipping of the outer layer of paint can be an issue. Yes, the Elmers glue WILL soften again if left to the elements. I built an earlier fairing for another motorcycle, and the paint chipped enough that water started getting into the glue, which then caused the painted surface to bubble and delaminate! It was a very rainy spring that year.
3) I have a full coverage motorcycle fairing that has lasted almost 20 years by using Elmer's glue to adhere the glass to the foam. Since the foam is soft, rocks kicked up from the road can and will chip the outer layer of paint. This usually happens down to the layer of Bondo Spotting Putty for some reason, even though the surface was sanded carefully before priming and painting.
4) It's possible to glass the front of your new vehicle with epoxy and then use Elmers for the sides and back, where rocks getting kicked up will less of an issue. It's certainly something to think about.
5) I don't think that Elmers has an issue with UV light similar to what the epoxy has. This could certainly be a plus in your favor for using this glue.
6) You obviously can only add one layer of glass at a time with Elmers (with 6 ounce cloth).
7) I have two DVD's regarding airplane construction of glass over foam, and both the Rutan and Arnold copies both make full use of Epoxy resin on their builds.
EDIT after readings 123's post.
7a) The foam/fiberglass fairing has not shown any tendency to crack or otherwise show a degradation of performance through all types of road surfaces, rain storms, snow, extreme summer heat. As mentioned, road stones seems to be the biggest issue with foam over fiberglass. If done properly, you should not have to worry about cracking.
At least you have some facts and figures to mull over.
Jim.