I have read and studied your complete build log a number of times.Looks awesome, It is very inspiring! I have wanted to take a crack at a composite build but doing the female molding has always discouraged me. I like the idea of using a male mold. I have a couple of questions,(1) What was your lay up, FG weight, layers, type of resin etc? (2) when you glassed the plug did you apply any mold release after waxing? (3) When you glassed the plug did you mount it on something so you could rotate it during the lay up? Also what type of primer are you using? If I missed any of this in the build log I appologize. I look forward to seeing your wing build, after discussing hot wireing. Thanks for all the info.

Lt599

Lt599, thanks for asking. First let me say I got a lot of info from reading John Morgans builds. Also great info from Tumbler ( Molding the blaze) on the resin etc. I did learn what NOT to do, and what I would change.

I used 3- layers of glass, 4oz, really only figures out to be 3.7oz. Next time around would only use 2 layers of heavier glass. J Morgan suggests around total galss weight 10-12 oz sqyd. This would of course depend on size of fuse.
Two layers will give you the same strenght, but you lose the weight of the extra coat of resin. When I glassed the plug originaly I just used some bondo glass from Menards, when it cured, I sanded it down and put on a thin layer of resin, sanded, wet sanded and filled as needed. Came out smooth as a babys butt. I didn't do it on the final pull, ( my mistake) too easy to sand through the glass.

What you would use for resin is your choice. I know lots of guys here like the West Systems.

I used US Composites #635 4:1, a little less working time than the 3:1
http://www.uscomposites.com/epoxy.html Theres a great thread in the composits forum on different resins. http://www.rcgroups.com/forums/showt...mparison+tests

I used the Partal #10 release. http://www.uscomposites.com/moldrelease.html

I did make a jig to hold the plug. Nothing fancy, just some ply I had for a base and put 2 uprights on the ends. Inserted (epoxied in) two large dowells into the intake and exhaust (drilled for 1/4" rod as axels) so I could remove them. It worked Ok, but broke loose in the white foam I used. From now on, only PINK foam for me! Much better in so many ways.

As for primer, I used Rust-Oleum Painters Touch Ultra Cover 2X. wonderful stuff. Guess that covers it. If you have any more questions, just ask .
Mark

Mark awesome work.
The Y/A airfoil you posted is not reflexed.

Thanks Kevin . Undercambered?

Yeah...it looks like it is....unless you have it upsidedown then it is reflexed .

At least I know what reflexed looks like. And the airfoil is right side up.

the bvm airfoil on my fury is reflexd a tad at the root .but the tip looks like a normal airfoil.

had a wing with under camber on the tip ....not very good for jets.just my experience,kinda tip stallish,a smaller wing with eppler semi sysmetrical foil landed slower ,with flaps.under camber has more drag.just my 2 cents.they work good for gliders

Air Sally,
I was assuming that WITH washout this would have great low speed handling...with out washout..tip stalling would be mandatory !

Just so you know, the airfoil of the Starfire I got right from Hans Peter Hofer
He drew it off of his Starfire V2 He did say it should have 2* washout.
I won't suggest that I know all that much about airfoils, just made the assumption that it flys the Starfire well. why not the Sabre. There's that assume thing again.

Thanks for the input. Just want to get the right airfoil. PLEASE, feel free to add your suggestion for a airfoil. Just have to have 1" thickness for retract units. Going to draw out the wings tonight so I know where they will be in relation the the thicknees in that section of the wing. Root cord will be 17.25".

Originally Posted by CoolerByTheLake

Lt599, thanks for asking. First let me say I got a lot of info from reading John Morgans builds. Also great info from Tumbler ( Molding the blaze) on the resin etc. I did learn what NOT to do, and what I would change.

I used 3- layers of glass, 4oz, really only figures out to be 3.7oz. Next time around would only use 2 layers of heavier glass. J Morgan suggests around total galss weight 10-12 oz sqyd. This would of course depend on size of fuse.
Two layers will give you the same strenght, but you lose the weight of the extra coat of resin. When I glassed the plug originaly I just used some bondo glass from Menards, when it cured, I sanded it down and put on a thin layer of resin, sanded, wet sanded and filled as needed. Came out smooth as a babys butt. I didn't do it on the final pull, ( my mistake) too easy to sand through the glass.

What you would use for resin is your choice. I know lots of guys here like the West Systems.

I used US Composites #635 4:1, a little less working time than the 3:1
http://www.uscomposites.com/epoxy.html Theres a great thread in the composits forum on different resins. http://www.rcgroups.com/forums/showt...mparison+tests

I used the Partal #10 release. http://www.uscomposites.com/moldrelease.html

I did make a jig to hold the plug. Nothing fancy, just some ply I had for a base and put 2 uprights on the ends. Inserted (epoxied in) two large dowells into the intake and exhaust (drilled for 1/4" rod as axels) so I could remove them. It worked Ok, but broke loose in the white foam I used. From now on, only PINK foam for me! Much better in so many ways.

As for primer, I used Rust-Oleum Painters Touch Ultra Cover 2X. wonderful stuff. Guess that covers it. If you have any more questions, just ask .
Mark

Thank you for all of the information. I have researched building with composites for some time. Its nice to get a specific lowdown from someone that has just done it. So depending on the fuse size maybe 2 layers of 6oz instead of the 4, that makes sense about saving the resin weight. I agree with you on the foam. I use alot of the Dow Blue and love it. I believe it is the same as the pink just different manufacturer. One more question, since your fuse is all rounded what did you apply the resin with to get it as even and smooth as possible (I know the fun of sanding glass) I assume you used a brush? Thanks again, your build is looking great. Greg

Yes I think the pink and blue are the same, at least close enough. Just used some cheapo brushes from the local building center. (Menards in my area, we also have a HD ) I think when I sanded it, I started with 100/120 grit, just to knock it down a bit. Then 150, 220, and finally 400 /600 wet and dry. When ever get to the point where its ready to paint, I may go a little higher on the wet and dry. But 600 gives a real smooth finish. What size were you thinking for a fuse?
Mark

Not sure yet. I have been planning a F35. I built a semi profile powered by a 70mm. I have flown it many times with different batterys, added gear etc. to come up with some numbers on thrust to weight. But if I am going to glass one I will go for a 90mm. I would guess at aprox. a 48" fuse. Greg

I would love to report some progress, but nothing to show. The weekend plan was to get nose gear doors cut out and gear installed. However, after the little brown truck came, I opened my parcell and to my dismay found the strut I had ordered was WRONG! Damn. I had ordered an offset Left Handed one. To me thats what this pic dictates. I guess Robart decided that the scissor joint is in the front, not the back!! At least Tower sent me free UPS return postage. I suppose I won't get the right one back till after next wekend.

A lesson learned. So for anyone who might want to order offset struts, make sure FIRST you know how they determine left/right.

Mark

siccors should point aft