Getting fiberglass to conform to laps

When glassing multiple planks with one piece of cloth draped over, how do I get the cloth to conform to the lap seams without rounding the fillets and keeping the "clinker" look of the lap seams?

Thanks in advance for the input!

Eric


4 replies:

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RE: Getting fiberglass to conform to laps

cloth, in general, cannot take a sharp bend/edge unless there is some force that is holding it in place (e.g., pulling it tights around a shape or using vacume pressure to suck it against a piece)

can you describe a bit better where you are trying to place the cloth?  is this the inside of the boat?  a picture might be useful in generating some ideas.

if the angle is oblique enough, you can maintain what looks like a relatively sharp edge between two laps (like what you would see in the inside of an annapolis wherry). you may have to baby the application a bit and push the cloth into the corner/edge after the epoxy has started to kick/acheived a sort of bubble-gum consistency.

 

 

RE: Getting fiberglass to conform to laps

   The Chester Yawl manual calls for glassing the garboards. In addition, it calls for laying a second piece of cloth over the garboards that extends over planks 2 and 3 on both sides of the hull, adjacent to the transom on the hull exterior; Here is a copy/paste of the manual: "Cut a triangular piece of cloth large enough to cover the fi rst, second, and third planks to approximately 36” forward from the Stern. Wet out with un-thickened epoxy."

That part of the hull at the stern sees the planks fairly "contorted" in order to conform to the shape of the "wineglass" transom, yet the same area on the interior also receives glass. Is this step necessary on the exterior? If so, do I just accept rounded laps to glass over? Do I need to glass one board at a time and use a straight edge wrapped in packing tape to push the glass against the seam while it cures, then move on to the second plank, and so forth?

Eric

RE: Getting fiberglass to conform to laps

     Preventing bubbles along the laps is very difficult, I waited until the epoxy was green and pushed the cloth into the corners where it mostly stuck. There were still a few bubbles the next morning, but they sanded out easily and were filled by a later coat of epoxy. If I was to build another Yawl, I would use a lighter wt cloth to aid in conforming to the shape of the laps. Actually, I probably won't build another lap strake boat due to the difficulty in sanding all of those planks: give me something with wide sheets of ply that I can use power tools on next time!

RE: Getting fiberglass to conform to laps

   Thank you both for the input! I just made a plastic straight edge that I am going to use to "tuck" the fabric into the seam when it is green (as you mentioned), then I will do the same with planks 2 and 3 (just one at a time). Hopefully, this will work, too!

Eric

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