Jump to content
Sign in to follow this  
Brett82

The Skorpion got stung

Recommended Posts

Brett82

Thanks Pete

I think "calm down" is good advice. Taking the pictures was the first time I had looked at it since putting it in the bags on the slope and it looked worse than I remembered which got me a little panicked. 

I will definitely take it slow and she is well worth it. I think this is going to be a long project over the next 3 or 4 months if needed. I also think that's another good point, I will choose a section and post a thread with some pictures specific to that repair. Get some advice and work on it. Once done move on to the next. Please continue offering advice on here for each repair, it will help me decide were to start.

Thanks mate, and sorry to make you see your old plane in such a bad way...:(

Share this post


Link to post
Share on other sites
Phil.Taylor

The fuselage is fairly straightforward - the hardest bit is getting it straight - which is a lot easier if you can borrow another one & make a jig !

the basic routine is:

1. thin cyano into the breaks, to hold it all together

2. file/sand/feather the edges of the break to make space for new epoxy/glass

3. lay in epoxy/glass (lots of it) & leave to cure solidly

3. file/sand back the excess epoxy & glass

like on the Radical nose-job thread:

 

  • Like 1

Share this post


Link to post
Share on other sites
satinet

As said above its probably doable but it's a labour of love. Just the time to fill off and paint repairs to decent standard is very time consuming.

 

The amount of time it will take you could get a second job to pay for a new one. Only half joking.

 

Something to do as a laerning exercise but a lot of work. If the joiner box is snapped you are in Problemsville. Population you.

 

You will probably need to buy tools like a small sander e.g proxxon (€£€) and you will definitely need lots of composites. Good expoxy, thickner, syringes, tows, cloth, filler, paint etc.

Personally i think it might be rest in pieces for a skorpion.

  • Like 1

Share this post


Link to post
Share on other sites
Brett82

Thanks again Phil, sounds fairly straight forward if I take it slow, one step at a time. I will go through that thread and make sure I'm really familiar with it. 

Definitely a labor of love Tom but the Skorpion helped me get a sub 40 in my first full competition. She is worth it, :D

Can I just ask, what is that 3M spray used on carbon/glass to stop it falling apart on the edges when you cut it?

Thanks for the help so far everyone, Im going to have to get some shut eye and pick this up in the morning. 

Share this post


Link to post
Share on other sites
heli_bee

If you feel the need to watch a dvd on how to repair everything, have a watch of the "Glider Repair Lab" set from Paul Naton and Radio Carbon Art.

Well worth the money. It allowed me to repair my smashed 2m Typhoon back to full strength.

 

  • Like 1

Share this post


Link to post
Share on other sites
Brett82

Good idea, thanks mate. I will have a look at that. 

Share this post


Link to post
Share on other sites
satinet

3M 77 spray. Stuff like 'spray mount' works fine too. Carpet adhesive isn't fine enough.

 

  • Like 1

Share this post


Link to post
Share on other sites
isoaritfirst

I think Pete has given some good advice. Use it as an excercise in learning how to repair. 

Be careful of taking in too much info. It may just lead you into an area of indecision or concern about your ability to repair. 

Just have a go - slow, on days when you have nothing better to do. 

Although it makes sense to see if you can repair the wing first. I think I would do the fuselage , just because it will be the easiest and may give you a little confidence. 

Most of the techniques I use I just discovered for myself from "doing it". 

Laying carbon cloth onto the fuselage I now cover one side with masking tape before wetting it out. This helps it to be cut and handled to shape. As it dries I put it in a put the work in a plastic bag and every hour or so go and squeeze it again to ensure it is firmly down and epoxy has been removed as much as possible. It seems to work almost as good as vacuum bagging. 

  • Like 1

Share this post


Link to post
Share on other sites
oipigface
10 hours ago, satinet said:

 

Just the time to fill off and paint repairs to decent standard is very time consuming.

 

 

I wouldn't bother trying to make it look good. It needs to be as structurally and aerodynamically sound as possible. At one of the first international events I went to, I met an Austrian pilot whose Pike was a mass of repairs, but still flew as if was new. He pointed to each scratch and patch and recounted what had caused them: 'Hit a tree.' 'Hit the ground.' 'Hit the flag'. His repairs were like an array of campaign medals displayed proudly for all to see.

By the way, I disagree with Mike: start with the wing. If you can't bring that back to a flyable state, then there's no point spending time on the other things. (Unless you splash out on a replacement wing panel.) On the other hand it looks to me as if the spar is damaged. It is possible to fix a broken spar, but I've never tackled it in a mouldie, and I wouldn't recommend it to a beginner.

Another point: I found when I started to do repairs, that they took less time and were less difficult than they seemed at first. And the more you do the better and quicker you'll get at it. It's an investment worth making, and all part of the 'fun'!

  • Like 1

Share this post


Link to post
Share on other sites
oipigface

...and remember. The greater the ratio of carbon to epoxy, the stronger the repair will be. Applying pressure, either with tape or with a vacuum system is a good way of forcing epoxy out of a repair. Using breather cloth helps too. It absorbs the excess epoxy as it is squeezed out. 

  • Like 1

Share this post


Link to post
Share on other sites
oipigface

... and remember another thing: Keep the photos coming!

  • Like 1

Share this post


Link to post
Share on other sites
oipigface
12 hours ago, Brett82 said:

I have no idea how I would rebuild the root up.

As long as the structure (joiner box and spar) is sound, repairing a root to make it square and flat again is one of your least challenging jobs. If there are tears in the wing surface, jiggle them about until they fit as well as you can manage, then secure with a small amount of thin cyano. If you've got all the original bits, then follow Phil's advice: fit it all back together using cyano, rub it down and fill it. Small missing bits can be filled with epoxy and microfibres. Larger ones you may want to fill with balsa, ply or foam and then finish off with epoxy and microballoons, using tape again. Adding colloidal silica to an epoxy mix will help stop it run, but I sometimes don't use it on wingroots, because tape and gravity can produce very close to a flat face, if you tape it up and leave it root down to cure.

The main point is that it is not going to take any loads, so as long as it doesn't disturb the airflow, and it fits the fuselage profile it will be OK.

  • Like 1

Share this post


Link to post
Share on other sites
satinet

Supergling stuff back together isn't going to be strong. Imho you really need to do a strong repair, especially around the wing root. 

There is probably delaminations over the wing surface as well. Check to see if there are bubbles on the wing. They can be hard to spot.

I've repaired a snapped spar but 1) The Fumeister showed me how to do it and 2) the spar damage was a pretty clean snap so it wanted to go back together 

The bigger problem with the wing actually snapping in my case was it caused big damaged to the layup of the wing. It just rips the skins apart which delaminated the layup over a wide area. Each case is different though.

You really don't won't be rubbing down CF in your house btw.

  • Like 1

Share this post


Link to post
Share on other sites
Phil.Taylor

Brett - before you do anything - check the joiner boxes - if they are cracked / broken then its RIP Skorpion.

Phil.

  • Like 1

Share this post


Link to post
Share on other sites
Brett82
2 hours ago, oipigface said:

Larger ones you may want to fill with balsa, ply or foam and then finish off with epoxy and microballoons, using tape again.

Hi John. Thanks for all your advice, just in relation to the above will microballoons be ok? I remember reading that it makes the epoxy mix thick and light but takes away strength (never used it before so no personal experience). If so would silica or milled carbon fiber mixed in be another option or completely unnecessary? I do think I will use bulsa/ply/foam method for the root and fill it as you say then cover with tape. Seems to be a good way to do it.

1 hour ago, satinet said:

There is probably delaminations over the wing surface as well. Check to see if there are bubbles on the wing. They can be hard to spot.

Thanks Tom, I did have a look but thought it would be easy to spot so I may have not checked carefully enough. I will check again.

14 minutes ago, Phil.Taylor said:

Brett - before you do anything - check the joiner boxes - if they are cracked / broken then its RIP Skorpion.

I'm on the ball with this one Phil. I damaged the Willow boxes a while ago (and managed to repair them) so one of the first things I did when looking over the model was to check the joiner boxes. They look absolutely fine, I even tried putting a screwdriver down them and very gently applying pressure to the top and sides to see if I could spot any cracks appearing but couldn't see anything. Should have videoed myself trying to hold a torch and screwdriver up to the joiner box while still having enough room to see inside, I could have won 250 quid... :lol:

 

Any ides on the 3M spray? Anyone...

Share this post


Link to post
Share on other sites
Brett82

Somehow I missed a whole bunch of replies that only showed up after my last reply, thanks guys. I will read through them again and ask if I have any more questions.

Share this post


Link to post
Share on other sites
Brett82
5 hours ago, satinet said:

3M 77 spray. Stuff like 'spray mount' works fine too. Carpet adhesive isn't fine enough.

Great, thanks again Tom.

Thanks Mike, some very good advice there. I must admit, if Tony's friends can help I might just take them up on it because as much as I do want to learn I would prefer to learn on something not as drastic. Saying that I am actually looking forward to the challenge and if they cant help then I will definitely go ahead with it no matter what. One step at a time, slowly, without trying to rush it. I'm sure there will be a way to repair the spar so its not worrying me right now.

 

Share this post


Link to post
Share on other sites
martynk

Before I glue anything, I would a foam jig - top or bottom - whichever side has the most impact damage. Make sue the wing will sit flat in the jig then attempt a skin repair on the side facing you. If you can get that rigid enough and straight enough, then start working on the spar from the other side - you may need another jig. Splice/brace the spar - replace any split sections if possible, then repair the skin. Flip over again and clean it up.

Not an easy task and it will never look new but its probably doable...

  • Like 2

Share this post


Link to post
Share on other sites
Brett82

Thanks Martyn

A jig is a good idea and I think I will need one for the fuss and the right wing. Because of the twist its going to make it even more difficult so if someone has a Skorpion I can borrow to make a jig then I will appreciate it. Don't need it just yet though, I'm going to open up the wing and take a look a the spar as a first step. From there I will decide the best method of proceeding with the repair. 

For both wings I like the idea of making a mold from a little further down the wing, covering it with film first then laying up some carbon on top and covering the carbon with film again as it sets. If I make it big enough or do two then I can use some on the inside as a brace or an area to glue to and use the other as a skin making it the right size to fit into the damaged area. I would reinforce the inner carbon with a block of balsa or foam to help with compression strength. Hope I have explained that well. Any gap between the repair and the original skin would then be filled in with filler and sanded.

  • Like 1

Share this post


Link to post
Share on other sites
Brett82

Any thoughts on the below...

sorry, just realized I didn't draw it 100% correct. The first picture shows the brace as an L shape, that's correct, the second and third picture would also have the brace in an L shape so there was an are to glue to on the side and back. The root would then be guilt up as Johns comment above, balsa and epoxy with microballoons.

Wing repair1.png

Wing repair2.png

Wing repair3.png

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Restore formatting

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Sign in to follow this  

  • Recently Browsing   0 members

    No registered users viewing this page.

×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.