Sukhoi 29KS

[Rod]

Reverse masked the seam and did the other side of the cowl. I paint thickened resin onto the foam then smooth the glass down onto surface and apply more resin. I then smooth the second layer of glass down onto the first and add resin to any dry patches.

[Rod]

Glassed the pipe hatch and the carb air intake separately but they will get joined together later.

[dpoles]

How is that eppler airfoil for 3d?
Is it a "scale", pattern or 3d optimised airfoil?

thanks
sweet work!

[Rod]

Hi Dpoles
Good question I have been wondering that myself. Give me a bit of time to research this some more and give you a reasonable answer. The one that springs to mind is that it doesnt mater too much.

[Rod]

Masked the seam line along the keel. This gives a nice hard surface to sand on. If you have any overlaps of glass on the foam it is really hard to sand smooth as the foam tends to compress under the sanding block then spring out again leaving a lump that just wont go away. Got the 2 layers of glass on, this fuse is really using up the glass especially with 2 layers. Will probably buy a 100 meter roll for the mold as I think I will need about 25meters. The mold will be made using epoxy as it has got alot cheaper in recent years.

[brusty]

Thats looking great Rod. most interested to hear you saying you will mould in epoxy. I have heard Mike B talking about doing this, so am interested to hear your layup. I would have been concerned about sinkback and getting the cloth imprint, I'll be very interested to hear your comments and subsequent result and experience. Have you used epoxy as a mold to any degree previously ? With the Raven mold, I used a tooling gel, some vinylester and profiling resin, and was most impressed with the result, but at a cost, and considering the number of models I will pull, I guess it was overkill. the only plus for me is that a friend who has a fibreglass manfacturing business will let me take a drum of profiling resin away when he has one open, and I only pay for what i use!!
Cheers, Barrie.

[Rod]

Hi Barrie
I have been using an epoxy system for mold making for quite a few projects now. I will keep this one simple with no new techniques. The mold layup will be Gel coat 3layers of epoxy/microfibres/tinter then 6 layers of 200 gm glass.

[brusty]

Rod, Thanks for that, more questions, 1. what are the mirofibres, is that the glue powder and how much by volume do you add to the epoxy ? 2. what do you use as a tinter ? 3. how do you apply the "gelcoat" just brush it on like tooling gel ? I'm very interested, Cheers, B.

[Rod]

Hi Barrie
Micro fibres are a West system product. It is intended as an additive to resin to make a glue. I mix it in till the mixture wont run. At the moment I am using a powder called general purpose thickner. I tint it so I can see it, any dark colour will do. I use any sort of coloured powder usually concrete tinter, water based paint powders are good too. I just brush it on, let it jel (just) then another coat, let jel then another coat and start puting the glass on straight away.
Best layed plans! I cant get any 200 gm glass for the mold at the moment so I was talked into using chopped strand mat. This has a powder binder compatible with epoxy and is 450 gm so builds up much quicker.

[Rod]

Glassing is all done. Got the first coat of epoxy and microballoons on, the colour is from the microballoons. Have also sealed all the exposed MDF with epoxy thinned with methelated spirits (wont attack foam). This is where the hard work starts. Sanding sanding and more sanding. I expect the pattern finishing to take a couple of weeks so we wont see alot of visual progress. I will start on the foam cutting though as soon as I give the CNC foam cutter a birthday.

BTW you can see my 120cc camera heli in the background, but that is another story.

[Neogenesis]

Is that one giant helicopter I see peeking out of your garage?

Neo

[brusty]

Hello Rod, thats looking good. Can you fill me in the epoxy micro balloon coating. What mixture do you use, and do you just brush it on ? How many coats and sandings might you expect to have do ? Sandings real fun aye....Yeah Right