Here is kind of a quick look at how I made my splitter board and mold for my wing. I am far from an expert but a couple of people asked so hopefully they will try themselves.-OH BOY the UPS guy just dropped off my new Futaba 8FG- I will do this before I dig to deep into that.

First off you need to make a splitter board that divides your plug be it a wing like this one or a fuselage. I used some melamine shelving material from home depot as epoxy doesnt like to stick to it.

#1 I layed out the dihedrial onto one piece. This will end up being the frame.

#2&3 I cut it out with a jig saw and screwed the frame together. Make the frame several inches wider all the way around to give yourself room for a mold flange

Next,

#1&2 Screw the surface onto your framework.

Next,

#1 On this wing I used some double sided tape to hold it in place on your splitter board. For the fuse I used some clay from the craft store to hold it in place and square and level over the splitter. Just make some clay balls and stick them to the splitter and stick the fuse to that. The idea as you will see is to get a very accurate outline of what you are molding.

#2&3 Use a square as in the photo to mark some dots or whatever all around the edge.

#4&5 Connect the dots to make an outline.

This is a great topic. I've always wondered how to get the cut out to match the part.

Next,

I used a jig saw to cut out the splitter, I angled the cut to help when I do the edges. I also screwed some wood to the back to help stabilize the wing while I do the edges.

Next,

I sprayed the wing with some PVA and carefully placed it in the splitter trying to be exactly in the center all the way around. This takes some time and patience.

Next,

I sprayed the wing with some PVA and carefully placed it in the splitter trying to be exactly in the center all the way around. This takes some time and patience.

OOps on that last one

Next,

To get rid of the rough edge I used some bondo all the way around, be neat here as you dont want to get it all over just squish it into the gap.

Next,


After the bondo dries pop the wing or whatever out ( That is why we PVAed it ) and sand the bondo down flush. Be careful not to get to many deep sand scratches in your splitter

Next,


#1 We want to seal that little tiny gap between the splitter edge and in this case the wing edge. Make sure your part is clean and well waxed with a good mold release wax at this point.

#2 I used some tub and tile caulk to seal the edge, put a bead down only about 4 or 5 inches at a time.

#3 use your finger to spread.

#4 gently wipe with a damp paper towel to leave only the gap filled. Only do 4 or 5 inch long sections at a time.

Next,

T0 make "keys" to align your mold halves while joining I used these urathane furnature feet. Just place them around.

That is all for tonite I will do the mold here tomorrow. I want to go look at my new radio I will probably need to get Gary Schmidts and Jimmy Allens help thats fair isnt it? Build them airplanes and they help me with this complicated stuff.

Until tomorrow
Dave E.

All great stuff Dave, thanks..

OK now that you have your part secure in the splitter board lets mold it.

First is to wax the plug and splitter board 5 or 6 times allowing an hour or so between applications. Then I sprayed a couple of light coats and one wet coat of PVA.

#1 I laid out some marks so I knew how far out I wanted my mold flange to be.

#2 This is the surface coat I used I got it from Aircraft Spruce, you can also make your own surface coat by mixing some epoxy and thicken slightly with cab-o-sil and some graphite powder.

#3 This surfacer dries pretty fast when in the cup so I only mixed about 200 grams at a time.

#4 Once all covered let it tack up very well so when you touch it it doesnt come off on your finger. Make sure to smoothly brush it into all of the corners as to not trap any small air bubbles.

Next,

#1 I mixed some epoxy and cab-o-sil again and brushed it into all of the corners where the glass would have a tendancy to not conform eaisly.

#2 I put 2 layers of 2 oz. and 6 layers of 6 oz. cloth over the mold. This is about 1/2 of what I used but I stopped there as I didnt want the mold to get to hot as the epoxy kicked. If it gets to hot you run the risk of melting the wax and having your mold and plug not come apart. ( Dont ask how I know this )

After this kicked and cooled but still tacky I added another 6 layers of6 oz. If I did it again I would let that kick and add another 6 layers.

Next,

I made a steel frame for the wing mold if you dont have access to a welder you can do it with a good hard wood like oak as I did on the fuse mold

Next,

I roughed up the steel tube and the mold mixed up some epoxy and chopped glass and glued the frame to the mold half. This was all done before it is separated from the plug and splitter. Let this dry.

Next I took the splitter board off the mold being careful not to release the wing from the mold half. You will need to clean all the gook from the edge of your wing plug ( remember the tub and tile caulk ) It cleans up eaisly though. Then you will need to wax and PVA as you did before and lay up this half as before. When dry cut the edges all the way around your mold and apply the frame to the new side. Try to avoid the temptation to remove the plug until you are all done.

#1 The mold after second half was all trimmed and frame is lightly clamped in place to dry.

Next,

This is the fun part gently pry your mold apart I use a 6 inch wide flexable putty knife it doesnt take much. And then check out your new mold!

For the plug on this wing I cut a foam core sheeted it wit 1/16 balsa glassed primed and painted it.

Thats it nothing real hard or expensive just a little time. Now I am back to work on the three for the june basin race.

Looks great Dave.. I'm hoping to get back to mine shortly.. Why is it that life always gets in the way of model airplanes?

I realy enjoyed this post. How long from starting your plug to the finished mold?

Hey Randy,

Sorry so late, I guess if you had a plug all ready and were kind of motivated you could do it in 3 days. Day one splitter, Day two first half, Day three second half.

Dave E.