Berkut Kit

[tonyslongez]

Lynn

 

I agree, but with the MGS its very difficult. I'm squeeching most of the excess resin out of these layups. With the MGS having such low viscosity I would have to add resin to the layup to make the peel ply work. I'd rather just sand it. I have a wonderful array of power sanders. They make your job very easy if you know how to use them.

 

Tony

[tonyslongez]

This weekend was very busy. Dale and I got to work on the canopy frames getting them ready for their layups along with the drip rails for the rollover structures.

 

Pic 1) Here is the front of the rear canopy frame and the rear of the rollover structure. Dale and I spent the latter part of the weekend fitting the canopy frames to the rollover structure. Not an easy thing to do. When it was all said and done we where left with a canopy frame rollover structure match of perfection. Dale did such a good job there is NOOO gap in between the frame and the rollover structure. We'll have to go back and sand the gap at least a full1/16in for thermal expansion cycles of the canopy and frame.

 

Pic 2) I dug out the canard out and started getting it ready for the shear web layups. It's cold in vegas at the moment. that can change of course overnight. I want to get the canard and wings layed up before it gets so hot that I have to fight the resin. I followed the video on making the jig for the canard I sighted the two (waterlines?) on either side of the canard airfoil with a " friken laser".

 

Pic 3) Here you can see the "LASER" indicating the waterline.

 

Pic 4) the waterline has to be perpendicular to the table this will insure that your canard lift tabs will be perpendicular to the canard for the correct incidence. I'll attach that aluminum square that you see to the table this will keep the trailing edge straight.

 

Tony

[tonyslongez]

Sorry gang I've been very busy at work not much time to post. We are however trying to stay busy with the berkut. I want to let everyone know that I'm going to sell my A-kit which is the canard and wings. The canard is almost complete and the wings are untouched. I have all the carbon needed to complete the wings except maybe 10ft of spar cap tape which you can get from wicks fairly cheap. I will post this in the for sale section as well.

 

Thanks Tony

[tonyslongez]

Today was a little busy for me but I was able to get a few things done. I've been reading the plans carefully for the "turndowns" on the rollover structure which later will become part of the drip rails for the canopy. Here goes.

 

Pic 1) First you have to use a piece of plexiglass or plywood which ever you pefer. I used plexiglass, you can see thru it which helps while your doing the layup. Here I have fixed my plexiglss to the rollover structure. You can see the bar going across the front of the rollover structure this is to keep the plexi flat against the rollover.

 

Pic 2) The top of the rollover structure has a cutout in the top this allows the canopy to clear the rollover structure when the canopy opens. You need a seperate piece of plexiglass or wood to cover this area. I used a piece of 18lb density foam I had laying around. The edge is tapered slightly so we have a nice trasition for the layup. The tape is obviuosly the realease.

 

Pic 3) Now that we have everything secured nicely. I ran a toungue depressor sized flox radius around the entire structure. the dark line you see on the plexi is the minumum overlap we need onto the plexiglass. As long as I go to that line or past it I'm O.K.

 

Pic 4) You have to allow the flox to get between the rollover structure and the plexi. This will make a nice crisp edge when it is sanded down to the rollover structure.

 

Pic 5) Once again I used the foil method here to make the layups perfect. This will look great when it cures.

 

 

Tony

[tonyslongez]

Dale and I where real busy today we got alot done on the airplane. Here we go.

 

Pic 1) We had to build a jig for the shear web attach points. Basically we are following the video here. I think it is the same method that is used in the Roncz plans. BTW if anyone ever wanted to know. The only difference between a Berkut Roncz canard and a regular Roncz canard is the carbon sparcap tape That's it everything else is the same. OH YEAH! I forgot you can pull +9g's with a berkut canard. The stock Long Ez and cozy canards are like wet noodles compared to the Berkut canards.

 

Pic 2) The shear web is layed up and the leading edge is dry fitted to make sure everything is straight.

 

Pic 3) This is a fast forward picture we took our time sanding the foam perfectly to match the airfoil templates this is where the skills of an unlimited hydroplane builder really come in handy. THis canard is dye straight. Damn that Dale is so good. After we layed up the spar cap tapes we did our bottom skin layups. Following the plans precisely. This is the last ply of uni just before we wet stippled it in.

 

Pic 4) I waxed up some mylar and and layed it over the canard squigeed out any excess resin. I was suprised how little excess we had. Tomorrow when this all cures and I peel off the mylar there will be a glass finish. I'm not going to do any micro fill on the canard. This canard is the one that I have for sale. I don't want anyone to think That I'm hiding anything with micro..

 

Pic 5) I removed the plexiglass from the rollover structure. The turndown came out very nice a couple of very small pockets to fill not a real big concern.

[tonyslongez]

Pic 6) I had some really heavy weight carbon Uni laying around not sure where I got it but it was perfect for what I was going to do next. Here's the story. At some point during the build of John Andrewjeski's airplane he said that they had filled the glass to glass area behind the turndown with a carbon "Rope" by taking several strands of uni and laying them inot the glass to glass depression. So here goes. You can see that I have several strands of uni carbon.

 

Pic 7) I thought in order to handle the rope a little easier I would tie the bundle every six inches or so, this worked great for the initiall wet out of the carbon. I had to cut the ties though to let the carbon form a little easier into the depression.

 

Pic 8) It's really hard to see here in this pic. the carbon strands really blend into the turndown. You can see how the rope filles the depression.

[Cozy1200]

Pic 4) I waxed up some mylar and and layed it over the canard squigeed out any excess resin.

You wax it? I'm surprised epoxy sticks to it in the first place.

[Neverquit]

"Tomorrow when this all cures and I peel off the mylar "

Sounds like its not supposed to Drew. But, to stay on the subject, why use mylar? Is that a plans step? Why not squeegee excess without it or at best, use 3 or 4 mil plastic then cover with peel ply? Mylar seems pricey but hey, you're building a pricey plane anyway.

[tonyslongez]

You wax it? I'm surprised epoxy sticks to it in the first place

Drew Yeah you have to wax the crap out of it. Epoxy will grab it and you'll have a tough time peeling it off.

 

 

why use mylar? Is that a plans step? Why not squeegee excess without it or at best, use 3 or 4 mil plastic then cover with peel ply? Mylar seems pricey but hey, you're building a pricey plane anyway.

Neverquit

I use mylar because it doesn't stretch. You can use plastic but it stretches, so as you stretch the plastic over the glass trying to sgueechy out excess resin the plastic will tend to shrink back to it's original state which can and I've done this introduce air into the layup if your not vacuum bagging.

Pricey! Yeah no kidding it seems no matter how good a deal I get on something I'm still rocketing toward 70k. OUCH!!!!!

 

Tony

[Marc Zeitlin]

Pic 4) I waxed up some mylar and and layed it over the canard squigeed out any excess resin.

I'm not sure exactly which layups you're referring to here, but _I_ wouldn't purchase this canard from you now that you've covered it with wax, and I'd recommend that no-one else purchases it, either.

 

The plans (LE, COZY) are very specific not to use wax paper and or wax covered cups when mixing epoxy - there are numerous approved mold release agents (PVA, etc.) and wax is not among them.

 

Putting wax in contact with the wet epoxy is very not recommended. You're begging for adhesion problems (or potential ones) down the road.

 

If I were you, I'd sand off that last layer of glass and re-do it.

 

And for next time, just use 4-mil poly sheeting. Doesn't stick to the epoxy at all, does what you want, and peels right off.

[tonyslongez]

Mark

I'm not sure exactly which layups you're referring to here

,

 

So rather than ask what layups we are talking about. You decide in all of your infinite wisdom to shoot off a post like this?

 

but _I_ wouldn't purchase this canard from you now that you've covered it with wax, and I'd recommend that no-one else purchases it, either.

I really wish you wouldn't make recommendations about buying the canard if your not damn sure about the materials and systems used in it's construction

 

Putting wax in contact with the wet epoxy is very not recommended. You're begging for adhesion problems (or potential ones) down the road.

 

there are numerous approved mold release agents (PVA, etc.)

I'm glad you made that destinction. There is a product that I'm using called chemwax mold release agent. Most if not all mold releases are a type of WAX

 

 

You wax the mylar with mold release wax 4 applications. First application is applied it drys you buff it and then apply the second and so on and so on. I never ever ever used wax paper or wax cups. I didn't use wax between the layups I didn't mix wax into the epoxy.

 

I want everyone to know that there is nothing wrong with this canard it is built with the same techniques used in the production of this aircraft. Mold wax release works on any surface not just mold surfaces. I didn't make up this technique I'm following basic molding practices by people who have been doing it for 30yrs or more in the AVIATION industry. I have experts that I converse with constantly to make sure I'm doing this correctly. I trust them with my life and I know this is done the correct way.

 

 

If I were you,

Your not.

I'd sand off that last layer of glass and re-do it.

You would do that and waste alot of time and propably ruin a perfectly good canard.

 

And for next time,

Please ask first then shoot.

 

just use 4-mil poly sheeting. Doesn't stick to the epoxy at all, does what you want, and peels right off.

It doesn't do what I want otherwise I would've used it.

 

Tony

[Lynn Erickson]

I'm not sure exactly which layups you're referring to here, but _I_ wouldn't purchase this canard from you now that you've covered it with wax, and I'd recommend that no-one else purchases it, either.

 

The plans (LE, COZY) are very specific not to use wax paper and or wax covered cups when mixing epoxy - there are numerous approved mold release agents (PVA, etc.) and wax is not among them.

 

Putting wax in contact with the wet epoxy is very not recommended. You're begging for adhesion problems (or potential ones) down the road.

 

If I were you, I'd sand off that last layer of glass and re-do it.

 

And for next time, just use 4-mil poly sheeting. Doesn't stick to the epoxy at all, does what you want, and peels right off.

I agree with Mark. what happen to the good old method of put on glass and resin and squeege it out the excess resin and you are done. peel ply is a good thing if you want to hold down the edge or if the surface is to be filled or another layer is to be applied. the plastic or mylar thing is not always a good thing, it does allow the excess resin to be move around under the plastic but the excess resin still needs to be removed from the top of the layup or it does no good to use the plastic. it does leave a smooth shinny surface but that is not what you want. it may look good to the novice builder but not someone who knows good glassing techniques. the surface should be rough as in sanding or peeled plied surface so filler or paint will stick. Some of the new glassing techniques I see used may be "very not recommended" techniques and may cause a dangerous layup. at best they all are adding another experiment into your experimental project. so next time you are at 15,000 feet in you project give some thought to the way you modified the plans glassing technique.

as for Wax or silicone , don't do it. don't get it anywhere near the plane until its the paint job that you are using it on.

when I do a pre buy inspection for someone I ask the question of type of techniques used. and if wax or silicone is in the answer the inspection is done.

[tonyslongez]

I agree with Mark. what happen to the good old method of put on glass and resin and squeege it out the excess resin and you are done

Gee I don't know maybe the mylar and plastic is just a little better way of removing more resin and making the layup lighter. I'm not arguing old techniques that's what they are OLD.

 

it does allow the excess resin to be move around under the plastic but the excess resin still needs to be removed from the top of the layup or it does no good to use the plastic.

 

I disagree have you used that technique? and have you vacuum bagged before? if so you may notice that the vacumm bagged part looks indentical to the part used with mylar or plastic how do you account for that. All your doing is removing air and compressing the layup. You can get more resin out with the vacuum bagging or using plastic or mylar. I like the mylar becasue it doesn't stretch you just have to put mold release on the back of it so the epoxy won't grab it. The same mold release that is used when you vacuum bag something into a mold. it doesn't know, it's just mold release. think of the mylar as the mold with mold release on it. Sgueechy out the excess resin, let it cure, walaaa a perfectly smooth light weight part. What's the problem???????????????????????

 

it does leave a smooth shinny surface but that is not what you want

So sand it.!!! Every part on this Berkut has been vacuum bagged every part has a smooth shinny finish

 

it may look good to the novice builder but not someone who knows good glassing techniques.

Well I'll have to call Dave R. and let him know that you guys think that shinny parts are for the novice builders.

 

the surface should be rough as in sanding or peeled plied surface so filler or paint will stick.

Did I at any point recommend that you should shoot paint or fill anything over a non sanded area?

 

Some of the new glassing techniques I see used may be "very not recommended" techniques and may cause a dangerous layup.

Oh!! and what New technigues are those? and have you see any of those dangerous technigues exercised here?

 

at best they all are adding another experiment into your experimental project. so next time you are at 15,000 feet in you project give some thought to the way you modified the plans glassing technique.

(yeah if your 80yrs old)Are you kidding me? They ALL? so if I just vacuum bagged the canard is that an epxeriment too? I don't feel that following the layup sequence to the T and sgueeching excess epoxy out with mylar with mold release on the back of it to make the layup as strong as possible is hardly modifying the Plans glassing technique.

 

as for Wax or silicone , don't do it. don't get it anywhere near the plane until its the paint job that you are using it on.

that's good advice. It's a good thing that I didn't use either one.

 

 

when I do a pre buy inspection for someone I ask the question of type of techniques used. and if wax or silicone is in the answer the inspection is done.

You mean if someone hasn't used a technique for doing layups that you are familiar with. You guys are going to have to get into the 21st century here. the bucket and brush is no longer going to be an acceptable technigue for layups.

 

Tony

[tonyslongez]

Marc and Lynn. this is for you

 

http://www.tmi-slc.com/products/main.asp?c=7&p=65

 

learn something.

[Lynn Erickson]

Marc and Lynn. this is for you

 

http://www.tmi-slc.com/products/main.asp?c=7&p=65

 

learn something.

that is what we are trying to do, keep you from learning the hard way.

there are many types of mold release agents and cleaners used in making molded parts. they are used to release a part from the mold. first off we are not using molds, hence the name Mold-less composite construction. putting on a release agent that has the potential to be left behind on the surface that can result in a delam at a latter date is just not smart. why do this when it is not needed in the first place. there are thousands of these aircraft that where built and they did not need to use it to complete their projects.

lets see if I have this right , if we buy a product and put it on the surface

to solve a problem that is not a problem in the first place, then do we need to buy the product that is used to remove the product that we did not need in the first place to solve the problem that did not exist? sounds like a government project, take the time to spend the money on something that they never needed in the first place.

[EW1066]

Okay, maybe I'm missing something here....

 

What difference does it make if a release agent is used or not. Does the release agent or the fiberglass know that they are not in a "mold"? From what I have seen this is the final/finish lay up. What is wrong with trying to get the best possible finish. Never in his post does Tony advocate the painting of an unsanded surface. He and Dale have spent a lot of time prepairing the subsurface of this canard to make sure the shape is as perfect as they can make it. What sense is there in introducing flaws in the surface through a poorly finished final layup. All they have done is use a vacuume bagging technique without the vacuume bag. Once again the release agent and the fiberglass dont know the difference.

 

My 2 cents

 

Vince

[tonyslongez]

they are used to release a part from the mold.

Yes they are,hence the mold release. Just like the mold release on the back of the mylar.

 

first off we are not using molds, hence the name Mold-less composite construction.

Does the mold release know that?

 

putting on a release agent that has the potential to be left behind on the surface that can result in a delam at a latter date is just not smart.

Now this one is interesting, I'm curious here. you realize that this is the final layup we are talking about. I don't do this between each layup... How can there be a delam? the release agent doesn't delam a vacuum bagged part why would it delam a non vacuum bagged part?

 

lets see if I have this right , if we buy a product and put it on the surface

to solve a problem that is not a problem in the first place, then do we need to buy the product that is used to remove the product that we did not need in the first place to solve the problem that did not exist? sounds like a government project, take the time to spend the money on something that they never needed in the first place.

 

There is nooooo problem. It's not a problem that I'm tackling it's just another way of removing excess epoxy from the layup. I've done nothing wrong using this technique. it works great the final product is strong light and requires less micro for the finish what's wrong with that?

 

I don't understand why Zeitlin charmed in here in the first place he's barely posted anything about what I'm doing. He certainly hasn't been instrumental in the recovery of this project. I doubt he would've known the first thing about how to fix this airplane. Or the technigues that the people I trust are teaching me. Marc do me a favor go play in the cozy forum where you belong.

You're just causing trouble here.

 

Tony

[Lynn Erickson]

Okay, maybe I'm missing something here....

 

What difference does it make if a release agent is used or not. Does the release agent or the fiberglass know that they are not in a "mold"? From what I have seen this is the final/finish lay up. What is wrong with trying to get the best possible finish. Never in his post does Tony advocate the painting of an unsanded surface. He and Dale have spent a lot of time prepairing the subsurface of this canard to make sure the shape is as perfect as they can make it. What sense is there in introducing flaws in the surface through a poorly finished final layup. All they have done is use a vacuume bagging technique without the vacuume bag. Once again the release agent and the fiberglass dont know the difference.

 

My 2 cents

 

Vince

the next layer of

glass, filler, primer or paint will know the difference and sanding does not remove the stuff it just spreads it around. anyone that has done the micro filling of a moldless surface will understand why making the surface perfect and smooth under the fill is a waste of time and money. unless the surface is so perfect that it does not need any filler and can be primed and painted it will need a layer of micro fill over the entire surface to make it true anyway. if they are introducing flaws in the surface through a poorly finished final layup. the the mylar would be a cover up of the flaws and not good practice. why use a practice that has been known to cause problems. this is a big problem with molded parts where the mold has been waxed or silcone has been used. it is common practice for molded parts where gel coat is used, or the molded surface is the final finish, but when the part is to be filled, primed or painted other types of release agents should be used. PVA is one that will not effect adhesion of other products as it is water soluble and easy to remove.

[EW1066]

Lynn,

 

So what you are telling me is that, in you experience and to your knowledge, there is no way to remove the release agent from the finished surface that will allow a layer of micro, or primer, or paint to adhere to it? I find that both discouraging and hard to beleive. Time will tell. However can we agree that, in so much as this is the final layup, there is indeed no danger of a delam? I don't beleive that the resources that Tony has at his disposal would advise him to take ANY shrotcut that may indanger his life.

 

Thats 2 more cents from my bank.

 

Vince

[tonyslongez]

Lynn

 

All I can say at this point is. There is more than one way to skin a cat. you use your methodology and I'll use mine. I'll put my layups against anyones anyday. I just don't have the time to teach an old dog new tricks.

 

Tony

[Marc Zeitlin]

I don't understand why Zeitlin charmed in here in the first place he's barely posted anything about what I'm doing.

Until now, there hasn't been any reason - it looked like you were doing a reasonable job.

 

I doubt he would've known the first thing about how to fix this airplane.

Of course not. I've only built two aircraft that have flown safely for hundreds of hours, am an aeronautical engineer working for Scaled, and have an A&P certificate. What do I know about composite aircraft, compared to a machinist (which I've also been in the dim, dark past) building his first airplane? You'll have to forgive me for my regrettable lack of humility.

 

Or the technigues that the people I trust are teaching me.

The issue isn't with the people you trust, or what they're teaching you, the issue was with what you wrote.

 

You did not state what layup it was that you were working on, nor did you state that you were using mold release. You said "I waxed up some mylar...", giving the impression that you were using wax on what COULD have been a surface that would have layups adhered to it later. In any case, as Lynn has pointed out, even if there would be no structural layups applied, you still want the finish micro/etc. to stick to the surface.

 

Mold release, depending on the type and it's compatibility with the epoxy being used, is probably OK - wax is not. And your description of vac. bagging is incomplete at best - generally (not always, but generally), peel ply is applied to the mold surface so as to give the finished composite surface some texture to mitigate the need for sanding after release and ensure that the mold release doesn't touch the surface of the glass, but the surface of the peel ply.

 

Marc do me a favor go play in the cozy forum where you belong.

When I need advice about where to post, I'll try to remember to ask you, thanks.

 

You're just causing trouble here.

That's pretty funny.

 

You should learn to accept constructive criticism better, without becoming both defensive and aggressive at the same time, and if you don't like hearing what I have to say (or what Lynn, or anyone else has to say), feel free to put me (or them) on your "ignore" list, or whatever it's called in a web forum.

[Lynn Erickson]

Lynn

 

All I can say at this point is. There is more than one way to skin a cat. you use your methodology and I'll use mine. I'll put my layups against anyones anyday. I just don't have the time to teach an old dog new tricks.

 

Tony

this old dog uses both old and new tricks. the difference is he is old enough to know when to use which trick so he can produce safe and lasting composite structures. I'm sure your layups are fine, it the stuff that is between your laups that is the concern. just make sure if you are going to use this new high tech release stuff with the 50 year old low tech composite technique us old dogs taught you that you use the proper high tech removal stuff, as it has been proven that the old dog technique of using sand paper even in the hands of a young guy does not work on this new high tech stuff.

[tonyslongez]

Until now, there hasn't been any reason - it looked like you were doing a reasonable job.

More than reasonable job I would say.

 

 

 

Of course not. I've only built two aircraft that have flown safely for hundreds of hours, am an aeronautical engineer working for Scaled, and have an A&P certificate. What do I know about composite aircraft, compared to a machinist (which I've also been in the dim, dark past) building his first airplane? You'll have to forgive me for my regrettable lack of humility.

 

Walt Sally had an A&P and IA cert look at the quality work he performed. He thru that around like it was gosspel so I bought the airplane thinking that being a aircraft mechanic meant something like, you know what the hell your doing. WRONG WROOONG. I have noooo faith in your A&P Cert. AS far as being an aeronautical engineer. Doesn't mean you know how to build an airplane. Building airplanes comes from doing not crunching numbers.

 

You did not state what layup it was that you were working on, nor did you state that you were using mold release. You said "I waxed up some mylar...",

That is correct and you didn't ask before you sent a rather irresponsible posting. I'm trying to sell this canard and in no way have I jepardized it's integrity with my technique as I said before every part that has been made for this airplane has used that release It's called chemwax. So yes I called it wax. I haven't any problems with micro sticky to any of theother parts that wherre vauum bagged using the same exact release. I just don't see the problem.

 

Mold release, depending on the type and it's compatibility with the epoxy being used, is probably OK - wax is not. And your description of vac. bagging is incomplete at best - generally (not always, but generally), peel ply is applied to the mold surface so as to give the finished composite surface some texture to mitigate the need for sanding after release and ensure that the mold release doesn't touch the surface of the glass, but the surface of the peel ply.

I wasn't trying to describe vacuum bagging. There are several ways to vacuum bag something you have your way I have mine. I'm being taught by some of the best in the business. I take their advice before anyone else. and yes the release that I'm using is compatible with MGS.

 

You should learn to accept constructive criticism better, without becoming both defensive and aggressive at the same time, and if you don't like hearing what I have to say (or what Lynn, or anyone else has to say), feel free to put me (or them) on your "ignore" list, or whatever it's called in a web forum.

 

I can accept constructive criticism if that is what your giving me. Initially that was not your first statement on your post.

 

I'm not sure exactly which layups you're referring to here, but _I_ wouldn't purchase this canard from you now that you've covered it with wax, and I'd recommend that no-one else purchases it, either.

 

That's not constructive Marc thats being assumset you didn't even try to clarify where we where before you posted that. That's what got me defensive. If you had asked me more questions and clarified the wax/release and found that what I did was still wrong in some way not just different then maybe this would've gone alot better. I know you are smart guy but your delivery sux.

 

Tony

[Steve Innova]

Great....

 

So is someone going to go and start a new forum? We only have three now.

[Jon Matcho]

What difference does it make if a release agent is used or not. Does the release agent or the fiberglass know that they are not in a "mold"?

Of course not. The concern is whether all of the wax is removed before the next layer of glass is laid up onto it.

 

...feel free to put me (or them) on your "ignore" list, or whatever it's called in a web forum.

Amazingly, it's called an "ignore list" here.

 

So is someone going to go and start a new forum? We only have three now.

Needlessly stirring the pot for your own amusement!

 

 

I'm sure Tony knows that epoxy doesn't stick to wax (or any mold release agent for that matter) and in order to get the next layup to fully adhere you need to sand the heck out of the cured epoxy and remove ALL of the wax/agent.

 

I'm also fairly certain Marc and Lynn know a thing or two about the topic, and are basically just pointing out: "Why not just use plastic and avoid the wax altogether"?

 

Maybe 6 mil plastic would do better in the stretching department?