I am trying to use woven roving but the edges keep unraveling when I am doing the layup. Is there any trick for keeping the edges together? I was thinking of using some sort of tape that I could use to hold the edges together like low tack masking tape. The tape would be left in the mold so its adhesive would need to be suitable for use with vinylester. Can some one suggest a suitable tape or a different method to stop the edges coming undone?
This wont be any help if your infusing but if its wet lay up then I have used drywall jointing tape (the self adhesive mesh type) in the past its also good for spreading all over the back of lightweight carbon twills helps to keep the weave from distorting. When you wet out the resin disolves the adhesive on the tape and the dry wall mesh then easily lifts off the back. Best try a test piece first on a scrap piece of cloth to check the tape adhesive disolves with your resin.
Is there any reason you can’t cut an extra 10% and not wet that out over the mold?
I should have mentioned that I am using vacuum infusion and a closed mold so the idea of the tape is to hold the edges together and to a lesser extent hold the roving in place while I close the mold. So I can’t remove the tape, it will become part of the piece. Would there be any problem leaving the drywall jointing tape in the piece? Has anyone ever tried stitching the edges, maybe I could run one of those hand held sewing machines up the edge? No idea if the stitch would work but it could be enough to hold it together. I don’t have a hand held sewing machine so I said I’d ask before I buy one and try it out.
I was going to recommend using a hand held sewing machines.
You can also try super 77. After you cut the fabric you’re go g to use, lightly tack up the fabric with s,e super 7 adhesion spray. Then apply it over the mold. Super 77 can be found at Home Depot or similar stores. Just be sure to use it lightly.
Very lightly indeed.
Other tricks:
-keep handling to a minimum
-search for a denser woven roving
-change fabric orientation (if possible)
-use woven roving / csm combo
-skip woven roving at all, use multiaxial
-use Airtech “Tackstrip” along the edges
Or any combination of the above…