$56 Skymaster!
 

The Skymaster has arrived! showing all of it's 20-30 yrs, i have finally received the Skymaster 60 that i bought off of Ebay for $56. The fuse is full fiberglass (nice) and the wings are sheeted foam. it's a little rough around the edges but with a lot of tlc and expert advice from this forum i feel certain she will shine again. first, i will post overall photos, then i will post a few photos showing the flaws and wear.

david

RE: $56 Skymaster!
 

here are some photos showing the wear and tear. there are a couple of stress cracks in the fiberglass fuse, along with other areas that need attention. the wing has only 1 hard scuff on the end but mostly just needs to be recovered and have new retracts and servos added.

RE: $56 Skymaster!
 

how would one go about stripping the paint off a fiberglass fuse? this will need to be stripped, repaired and repainted.

david

RE: $56 Skymaster!
 

Looks Great!! Nothing too tough on that puppy to fix at all!! Is that part on the vertical which is chunked out foam with glass over it??

As far as stripping the paint....Ye-Ole Sandpaper... :D (If your careful..a DA sander comes in Really handy for this process!!)

As far as fixing the cracks, chips and delams:

First you'll want to identify the resin used in construction of the fuse (ie: Epoxy, Vinyl Ester or Polyester)...You will need to repair the fuse with the same material it's made of...You can't mix-match resins..Epoxy is not compatible with polyester and the repairs will not hold up and vice versa...

With a little experience..Vinyl Ester and Polyester are pretty easy to differentiate from Epoxy due to the Styrene odor present (ie: New Boat Smell)...You can usually smell them and tell weather it's polyester based resin or not (Wierd Huh)...If the fuse is old enough that the styrene odor has gone away...A light scuffing of the fiberglass with sandpaper will usually rejuvenate the odor enough to tell...

You want to remove any of the "Bad Glass" via cutting, sanding or grinding...Ultimately you want to remove as little material as possible..But it's important to get all the bad stuff out of there...If it's "white, loose or cracked" it needs go bye-bye before you go any further...Patching over a bad spot will result in a weak repair...

In the case of a "crack" you should stop drill at the end point of the crack prior to grinding...This will relieve stress and help ensure the crack will not go any further (Just like working with Aluminum)...

Then you want to "scarf" (taper) the surrounding fiberglass so that your repair glass can "feather" into it...You'll start with a smaller patch and then each additional patch will be slightly larger as to eventually blend into the parent material as necessary...How may layers will depend on the thickness of the original laminate and the material used for repair...(Probably at least three layers of .75oz cloth )

Aside from very small cosmetic type "dings"...Attempting to repair with just resin is not good...Fiberglass resin without cloth it has no structural value and will be weak...To fill a crack with resin only will result in a substandard repair which will be prone to failure...Also...Attempting to glass over a crack or delaminated area is no better and will be prone to fail...You must remove the bad material first... :D

If your planning to repaint the whole Airplane...I'd suggest first stripping the paint completely before you do any glass work...Paint can hide fiberglass damage...Once it's completely stripped then you can assess your airframe and put a game plan together for the necessary repairs...

It should be a fun little project!! If you have any questions or need any help just Hollar!! If it's more than you wish to tackle...Bring it to me and I'll take care of the glass stuff for a small fee (you let me fly her once or twice!! :D :D :D )

Here are a couple of links which may be useful?? :
http://www.fibreglast.com/contentpag...epair-123.html

Attached is a photo of some tools that make life much easier when doing this sort of stuff!! (note: forgot safety glasses.. :D )

Note: I disagree with the pictures of the fiberglass patch's as they are in reverse order...You first start with the smallest diameter patch and go larger as you work your way out...

RE: $56 Skymaster!
 

The rational for using the largest patch first is to get maximum contact around the damaged area to reinforce the fiberglass, then fill up the hole. I was told this years ago by a boat builder. Of course we don't need to be waterproof, but those holes can make some pretty interesting whistling noises...at speed :D
-Will

RE: $56 Skymaster!
 

If a crack is not too bad, a doubler from inside attached with CA will strengthen the area, then CA on the outside, be sure to sand as soon as the CA sets up. It gets harder as a few hours go by.

RE: $56 Skymaster!
 

Preface: I often have a tough time differentiating between home and work...I do stuff at home the same way I do it at work...Some may consider this overkill (It May Be for these Toy Airplanes??)


I suppose that's OK for boats...But it ain't how you fix Airplanes... :D

Using the largest patch first in effect reduces the strength of the repair to only one ply...The rest turn into "body fillers" and have reduced or no structural value...

As for a structural repair on an Aircraft component...All efforts are made to match the original density of material and then also matched in ply orientation from a stress/loads standpoint...All repairs are scarfed or stepped per ply with a minimum of 1/2" overlap (or per engineering)...It is accepted that a secondary bonded repair will not be as strong as the original laminate...Which makes it more critical that the repair be done in such a fashion to maintain the original integrity...You start with a small patch and grow in size on the way out...

Again...A secondary bonded repair will never be as strong as the original laminate...But if done correctly you can gain a large percentage of the original strength back...Workmanship and attention to detail are key elements in a successful bonded repair... ;)


There is a right way...And there is a "Not so right way" as I mentioned in another thread...

I imagine allot of folks would take an approach like this with these toy airplanes...I'm sure there are hundreds of repairs flying around out there which have used this method or similar...They may last forever??


I know this ain't the Space Shuttle!! I'm pretty much an arse who thinks somebody's butt will be in the seat... :D

RE: $56 Skymaster!
 

Navav2002, I don't disagree with you.

It is a question of what is "good enough" vs overkill, and is a personal choice IMHO

The question is "what do you want out of the repair?" If it's just to get an airframe in the air with the least fuss, then CA is fine. If it is to make it back to the original as close as possible with the least weight gain, then you are absolutely correct.

RE: $56 Skymaster!
 

True..

The one that would bug "me" is the crack on the side of the fuse...The rest are pretty minor and I'd consider cosmetic repairs...But the one on the side you might as well say the fuse is cracked in two (note: I havn't seen in person...Just judging from the photos)...This one **I'd** wanna treat as a load bearing structural repair... :D

If your familiar with the SkyMaster (or you might be able to tell from the photos??)...The upper portion of the fuse (Turtledeck) is removable for access to the tuned pipe...So the crack on the side is actually through the Fuselage portion of the Airframe...The Turtledeck is not effected...

Just My .02...

Chuck

Edit: FYI..Here are some better scans of some typical Aircraft Composite repairs...

RE: $56 Skymaster!
 

the crack on the side is the major problem, the existing patch on the back side did not work. the other issues are just cosmetic. fortunately i am willing to invest the time and money to do this the right way. in effect this will be a rehab thread vs a build thread. hopefully this will be a showpiece one day. and as for the crack being in the main body, not in the removable turtledeck, chuck is exactly right.

david

RE: $56 Skymaster!
 

does anyone have a photo of an original skymaster kit box or what the paint scheme was back in the day? i would like to refinish this plane as close to the original paint scheme as possible (if there was one).

david

RE: $56 Skymaster!
 

I think it looks Kewl...

RE: $56 Skymaster!
 

looks good, better than what it looks like now.

RE: $56 Skymaster!
 

i just picked up a set of retracts for the Skymaster. don't know if i overpaid, but i don't see them very often.

david

http://cgi.ebay.com/ws/eBayISAPI.dll...m=120240081922

RE: $56 Skymaster!
 

dhal22, You are so greedy!:):)Just kidding. I bid to $71.85 for those and it went over that before auction closing. I have a couple of spares and it is good that I did. I just finished my Atlanta refurb and one of the MK main gear retracts had a bit of friction during rotation from gear up to gear down. I was getting ready to take it apart and see if I could make it better when I remembered my spares. A brand new MK retract installed in its place. Enjoy my retracts that you bought.:):)

RE: $56 Skymaster!
 

i knew i would be outbidding someone here. it was just a matter of who. actually, i had put in a bid up to my limit and forgot about them until this morning. the skymaster used to have mk retracts so i was going to have to get them eventually.

david

RE: $56 Skymaster!
 

dhall22,

I don't think you paid too much for your retracts. I just bought a set of Rhom Air trike gear retracts for my DIrty Birdy and I paid $125.00 for them. Looking forward to your refurbish thread. I always enjoy seeing other peoples handy work.:D

RE: $56 Skymaster!
 

well, these are mechanical retracts. i have no problem with paying $150 for spring air pneumatic retracts, but the skymaster was originally built using mk retracts.

david

RE: $56 Skymaster!
 

Regarding the fiberglass repair, I think the way it shows with the order of patch size is the same as what they show in this West Systems epoxy marine repair video. They used pieces of glass mat, not weave or roving. They cut the pieces out, wet out all the pieces with laminating epoxy, then covered them (once stacked together) something they call "peel ply," which I believe is a type of dacron cloth. They slap the built up patch on the repair area, smoothing it out with the peel ply in place. Then the peel ply is removed, revealing a partially smooth surface.

RE: $56 Skymaster!
 

i'm very lucky in regards to the fiberglass repair. i live an hr or so away from navav2002, who has generously offered to do the fiberglass repairs and prep. being as it is one of his many areas of expertise, i am inclined to let him have at it. however the plane continues to sit, waiting to be delivered to Chuck (navav2002).

david

RE: $56 Skymaster!
 

it's been a while but the Skymaster restoration has begun somewhat. after consultation with Atlanta 60 (formerly navav2002) I have decided to remove the paint in advance of the fiberglass repair. The product Citristrip works very well for paint removal from fiberglass and fiberglassed wood surfaces. simply slather it on and 10-30 minutes later scrape (plastic scraper) it off. in this project the 1st application removed the old yellowed clear coat and some of the softer paint. additional applications removed the harder paint and the paint under the clear coat. some of the paint was so durable it took very firm scraping to remove. still a long way to go before the fuse is clean but a good start. after the paint is removed and the fuse is totally stripped clean it will be delivered to Chuck for the fiberglass repairs.

david

RE: $56 Skymaster!
 

more photos

david

RE: $56 Skymaster!
 

using a different camera is allowing me to only post 2 photos at a time.

david

RE: $56 Skymaster!
 

David,

Looks like you're making good progress on the plane. I'm sure Chuck will do a great job on putting her back into great shape with his glass work. A couple of things I've found while "restoring" old birds is that you need to cut and rehinge all control surfaces. Planes this old will have wood shrinkage that you can't see under paint/coverings and you'll find this out at the worst possible time. (how do I know???) It also wouldn't hurt to have Chuck check out the stab joint. These areas take quite a beating on pattern ships and, once again... old glue is NOT a good thing. On an old Tipo I restored I had to cut out the vertical post after removing the rudder and then completely reglass the stab in place. Fortunately on that one I could see the stress crack from the outside. It also goes with saying to really inspect the wing hold down plywood/bolts/glue joints. Good luck with your project...the more vintage birds we can keep in the air the better off we are.

Dan
Carolina Custom Aircraft

RE: $56 Skymaster!
 

the citristrip continues to work wonders. the fuse is just about cleaned. the canopy is undergoing the citristrip's efforts 1 more time. it had many layers of paint. a heavy coat working for several hrs only loosened the 1st few layers. i let a heavy coat sit for several hours on the final areas of the fuse and the paint just wiped off.

david