I started to fiberglass one tip on the right elevator. I wrapped the outside with cloth and used regular fiberglass to go over the seam and I think with some fiber-fil, it will turn out ok. My question is how do you close off the space on the inside of the counterbalance arm? I heard you put styrofoam in the channel and fiberglass over it. Must not be right because when I did it the resin ate the styrofoam to nothing. Unless I'm using the wrong fiberglass, I don't know. I tried wrapping the cloth over and around the edge and glassed it that way but obviously that's not how you do it either because now there's not enough room for travel when attached to the HS. I'm not a glass man and could use some tips on how to do it. I went down to auto paint shop, told them what I was doing and they gave me regular fiberglass for repair jobs. Is this going to work? Looks like it'll work on the top just not the channel.
Van's Air Force
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help fiberglassing elevator tips
- Thread starter ditch
- Start date
Allan Stern
Well Known Member
fiber glass help
If the resin ate the styrofoam it was the wrong type styrofoam. Regular styrofoam is resin sensitive. You need the foam that the composite builders use. Polyester resin from West System works well for fiberglassing. You are correct that you make a small plug the then lay up some fiberglass sheets over it to level out the end/edge. Then sand smooth and fill holes with some body putty and sand some more.
Hope this helps.
Allan Stern, RV 6A
N570 RV (My Girl)10 hours
If the resin ate the styrofoam it was the wrong type styrofoam. Regular styrofoam is resin sensitive. You need the foam that the composite builders use. Polyester resin from West System works well for fiberglassing. You are correct that you make a small plug the then lay up some fiberglass sheets over it to level out the end/edge. Then sand smooth and fill holes with some body putty and sand some more.
Hope this helps.
Allan Stern, RV 6A
N570 RV (My Girl)10 hours
Ah, that's the problem, wrong styrofoam. Went to home depot for the foam. I'll have to look elsewhere. So when you put the cloth on the foam, do you attach it to the inside of the channel? I tried up and over the edge but got to big for the gap I need when attaching to HS. Also, how do you attach the foam to channel? I assume the foam will stay there so it would have to be attached permanently. Just fiberglass it in? I don't want to get it to heavy and really throw it out of balance. Like I said, I'm no fiberglass man.
Polyesther resin will eat the foam, epoxy resin will not. Epoxy is your best bet for making glass parts, less toxic and stronger. I don't think there is a foam out there that resists polyesther resin, I have used many brands and they all work OK with epoxy but I normally use the blue foam. If you get a hot batch of epoxy it will melt the foam but if mixed properly it works fine.
lostpilot28
Well Known Member
I'm not sure if everyone here is talking about the same area that you were asking about. You said that you thought you needed to glass over the inboard area of the counter-balance arm on the elevator....I don't think you do. I didn't, and I've seen a few other RVs that didn't either. Come to think of it, I don't ever recall seeing one that had the inboard side of the counter-balance arm glassed in.
These are the areas that I want to do. I saw a pic of one that had the HS completely filled in but I can't see if the counterbalance are was done on the inside. I would assume that it was. Anyone else do both of these? As you can see, I tried fiberglassing over the counterbalance arm but didn't work. I need to remove the rest of it. Actually comes off pretty easy once you sand the edge. Might be trickier on the weight itself though.lostpilot28 said:
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lostpilot28
Well Known Member
The top picture you would glass in the back of the tip. But the bottom picture you would glass in the lead weight and that's it. At least that's what I did.
N941WR
Legacy Member
Greg,ditch said:
I'm not exactly sure what you mean by the "inner channel of the HS". On the part of the cap that goes against the rib, I left it open. I saw no need to close that off. Besides, if you do close the tip off completely, you will need to drill a small drain hole in the cap. Otherwise, you run the risk of it blowing up if you climb to a high altitude. This has happened with some of the fast glass builders on their wings.
<<I just want to make sure I do it right so someday in flight it doesn't loosen up and get caught when trying to operate the control surface.>>
Good thinking. Why not take a short pause for education and skills development before you proceed?
Consider the practice kit from Spruce (PN 01-15000). It includes a copy of Burt Rutan's Moldless Composite Sandwich Homebuilt Aircraft Construction, the best how-to composites introduction ever written. If you don't want the kit at least buy the text. There are things in there you need to know.
If you purchased polyester resin, throw it away. Switch to an epoxy resin system; West 105 with 206 slow hardener is a popular choice. Consider 8.9 oz satin crowfoot as your general use glass cloth; builds quickly, drapes nicely over compound curves. Pass on the overpriced West fillers; buy bulk micro, flox, and silica thickener. Use peel ply every chance you get. And if the work seems messy and ugly, you're doing it wrong.
Good thinking. Why not take a short pause for education and skills development before you proceed?
Consider the practice kit from Spruce (PN 01-15000). It includes a copy of Burt Rutan's Moldless Composite Sandwich Homebuilt Aircraft Construction, the best how-to composites introduction ever written. If you don't want the kit at least buy the text. There are things in there you need to know.
If you purchased polyester resin, throw it away. Switch to an epoxy resin system; West 105 with 206 slow hardener is a popular choice. Consider 8.9 oz satin crowfoot as your general use glass cloth; builds quickly, drapes nicely over compound curves. Pass on the overpriced West fillers; buy bulk micro, flox, and silica thickener. Use peel ply every chance you get. And if the work seems messy and ugly, you're doing it wrong.
Harland E. [n.m. u.s.a.]
Well Known Member
Did you trim?
Greg you mentioned that the counterbalance arm wasn't fitting.Did you trim the HS tip and fibreglass as per the plans??(crosshatched scribbles in the drawings) Alot of people are missing that on the plans,me included.I personally did not glass in the inner length of the counter arm because I didnt see that anywhere in the plans and I have seen a few examples of flying planes that did not do it as well.The picture of the tip you clecoed on looks allmost ready to trace a foam plug.I simply held a 3\4" peice of foam up to the open end (while clecoed in place)and SHARPIED the shape of the hole from the outside as a template then sawed it out with a big steak knife.I trimmed a little to fit it inside the cap and fiddled around until it felt\looked right.Took it all apart and wrapped the foam plug in SARANWRAP then put it back together with the foam in at a depth to allow for the glassing material.I then gently held the cap and plug in my benchvise(plug end down) did some final measurements on the HS and the fiberglass tip then did an internal layup against the foam plug just like Van's plans\drawings show.After it cured the foam plug popped right out becase the SARANWRAP does not stick to the resin.The rest of the work was done clecoed in place on the HS in the cradle vertically where gravity works with you---filling the cap flush to the edges and trimming the excess cloth and all the filling sanding filling sanding filling sanding takes place.BTW... I closed the gap entirely between the cap and HS,actually layed glass up to and on the metal to bridge the gap.Looks really cool.Some people dont.I hope this helps.I had never done any fiberglass work in my life but the results look awesome and some more experienced people looked it over and said it was all good to go.
Greg you mentioned that the counterbalance arm wasn't fitting.Did you trim the HS tip and fibreglass as per the plans??(crosshatched scribbles in the drawings) Alot of people are missing that on the plans,me included.I personally did not glass in the inner length of the counter arm because I didnt see that anywhere in the plans and I have seen a few examples of flying planes that did not do it as well.The picture of the tip you clecoed on looks allmost ready to trace a foam plug.I simply held a 3\4" peice of foam up to the open end (while clecoed in place)and SHARPIED the shape of the hole from the outside as a template then sawed it out with a big steak knife.I trimmed a little to fit it inside the cap and fiddled around until it felt\looked right.Took it all apart and wrapped the foam plug in SARANWRAP then put it back together with the foam in at a depth to allow for the glassing material.I then gently held the cap and plug in my benchvise(plug end down) did some final measurements on the HS and the fiberglass tip then did an internal layup against the foam plug just like Van's plans\drawings show.After it cured the foam plug popped right out becase the SARANWRAP does not stick to the resin.The rest of the work was done clecoed in place on the HS in the cradle vertically where gravity works with you---filling the cap flush to the edges and trimming the excess cloth and all the filling sanding filling sanding filling sanding takes place.BTW... I closed the gap entirely between the cap and HS,actually layed glass up to and on the metal to bridge the gap.Looks really cool.Some people dont.I hope this helps.I had never done any fiberglass work in my life but the results look awesome and some more experienced people looked it over and said it was all good to go.
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The counterbalance arm didn't fit because I tried to wrap the fiberglass over the arm instead of keeping it inside. I cut it out and now everything works good again. I checked my resin and of course it's polyester resin. Just my luck. Only put it on one elevator cap but everything turned out fairly nice. Still deciding if I want to mess around with filling in the counterbalance arm in the inner edge. They are nice and I've heard that almost everyone does it but here most are saying that they don't do it. Maybe I'll just leave well enough alone. I want it to be a flying machine not a show machine. Thanks for the info on how you filled in the cap though. I'll try that.Harland E. [n.m. u.s.a.] said:
Polyester and Urethane foam
I did a search and came up with some interesting info on this subject of resin and foam. It should be of interest to us that styrene foam is not used with polyester resin. Polyester is thinned with styrene and foam made of styrene is readily eaten up by polyester. Urethane foam, on the other hand, holds up very well and as you'll see from the links it may be even easier to work with than you could imagine. Also if you're looking for West system polyester resin, give up, they never made it.
http://www.shopmaninc.com/foam.html
http://www.shopmaninc.com/polyesters.html
http://www.shopmaninc.com/faq_foam.html
I did a search and came up with some interesting info on this subject of resin and foam. It should be of interest to us that styrene foam is not used with polyester resin. Polyester is thinned with styrene and foam made of styrene is readily eaten up by polyester. Urethane foam, on the other hand, holds up very well and as you'll see from the links it may be even easier to work with than you could imagine. Also if you're looking for West system polyester resin, give up, they never made it.
http://www.shopmaninc.com/foam.html
http://www.shopmaninc.com/polyesters.html
http://www.shopmaninc.com/faq_foam.html
