The soft mould will distort under vacuum, I would use something solid. You have to curve the roof if you put a DER on each of them. Easier is to just but a DER on the vertical piece along the curved edge, then glue that to the roof and add some more glass.
Tape, glue and fillets are amazingly strong. A decent overlap (1-2") of the same weight of cloth as what you are gluing/glassing to and there will be no problems. If you are worried about it, use 2 layers, one slightly wider than the other or both the same width but offset a little.
rob
I was thinking the the DER, but it does seem like there would ba an awful lot of cutting. I was also wondering if I could make the radius mould out of silicon or molding rubber or something flexible, and bend that into place so that I could make a curved DER. I was concerned that the vacuum would change the shape of anything flexible, but if the experts (that's you, btw <grin>) don't think it is a stupid idea, I might try a test.
On a slightly different topic, the simplest way to make the raider panels would be to make the hull as one unit, and the cockpit as a second unit and glue them together. I was concerned if that would be strong enough, since the beams are only under the cockpit, and it has to lift the whole ww hull assembly. would glue, fillet and tape be enough to hold it all together?- GardnerOn Sat, Mar 5, 2011 at 11:40 PM, Rob Denney <harryproa@gmail.com> wrote:
1" will be fine. Two layers of 400 db/12 oz, one 75mm/3" wide, one 100mm/4".
An alternative to cutting and shutting is to bend the table. Make a couple of full length supports from mdf, then lay the mould table on these, seal the joins and infuse. probably more work than it is worth.
If you do cut and shut, make sure you do the glassing with the roof upside down. Very messy otherwise, especially if you then fair and paint it.
Lots of other ways to do it, including a KSS deck edge radius, although this will need some cuts to get it to bend, but none are quite as simple as a router, glass and fillet. Glass the inside as well.
Our next build will have the join as part of the infusion, similar to the DER, but curved.
robOn Sun, Mar 6, 2011 at 1:10 AM, Gardner Pomper <gardner@networknow.org> wrote:
I am trying to work out an easy way to join the panels for making the Raider design. I have got it figured out on how to join most of the panels together in flat sections, where I can just overlap a flange that I include when I infuse the panels, but I haven't a good idea on how to deal with the coach roof.
I think I am going to change the design a bit to let the roof be a curve. I think I can do that by making cuts in the 25mm foam panel, like KSS does. This way, I can make the coach roof for each side out of a single 7.5' wide panel. My problem comes when I need to attached it to the topsides. Should I just round the edges of the 25mm panel, and then tape it to the topsides, then fillet the interior join? That seems relatively simple, but I only get a 1" radius on that curve, and I am not sure that will be strong enough.Other ideas?Thanks,- GardnerPasadena, MD