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Archive for September, 2011
Posted by Jim.Thompson | Sep 17, 2011 @ 07:25 PM | 5,047 Views
I have now modified the parting boards to suit the steel framed/epoxy sand filled sandwich construction. The pictures shows how I employed Larrikin Dave's idea of using cling wrap on the plug to mould the LE and TE infill shape.
It will of course be block sanded down to the parting board after curing.

Posted by Jim.Thompson | Sep 16, 2011 @ 02:45 AM | 4,803 Views
After reading this thread:https://www.rcgroups.com/forums/show....php?t=1506575 I have had further thoughts re. my wing moulds. I like the idea of steel reo, and always have. Adam describes how the glass can be balanced either side of the steel frame which avoids any likelyhood of warping due to CTE differences which apparently are very small anyway.
I am trying to find a source of Poraver beads, but if I cannot get some, will use sand or crusher dust as recommended.
It appear to be a very stiff and economical mould making method. I like it.

Posted by Jim.Thompson | Sep 14, 2011 @ 05:00 PM | 4,904 Views
I am now sanding and surfacing up the plugs. The very best tools for this job are the long sanding boards as suggested by Larrikin Dave. The enable all the waviness to be eliminated with many fill/sand cycles. It helps to place the plugs in differing light conditions to show up the slight imperfections.

I have meanwhile started a wing joiner bar mould. I am making it as an epoxy surfaced and plaster backed mould. This will serve as a trial for the main wing moulds which I plan to employ the same combination. I have incorporated several layer of light glass cloth after the usual tooling/surface coat to strengthen the face coat. The finally a coupling coat of epoxy and a dust with cotton flock before allowing to cure for at least 3 or 4 days.
Posted by Jim.Thompson | Sep 09, 2011 @ 08:03 PM | 5,660 Views
The wing plugs are being primed and surfaced. I've made the parting boards to suit and they just need some fine adjustment and finally some splooge on the LE. I'll do this after painting them using cling wrap like Larrikin Dave did on his build log.
Posted by Jim.Thompson | Sep 01, 2011 @ 11:24 PM | 4,204 Views
I have decided to build hollow moulded wings for this plank, inspired to some extent by Dave's (Larrikin) build log -https://www.rcgroups.com/forums/showthread.php?t=1461579 .
This will be my first adventure into fully hollow moulding.
I have carefully cut the foam cores and have vacuum bagged them with 2 layers of 185 gsm 4H glass. They are still in the mylars. I will strip them tomorrow and get started with the parting boards before surface priming them.
The plans are to do an epoxy surfaced plaster mould. This disscussion going on the other thread : https://www.rcgroups.com/forums/show....php?t=1485623 is helping me make a choice of combinations in this regard.

More later,