Patching

[Skyboltone]

#12923

Greetings All:
I have heard that Stewart Systems fabric glue is the best there is. I have two patches to make on my Rans S7LS factory build. One will cover a 3/4″ diameter hole punched in the side of the fuselage above the N number. The other will be larger, perhaps 6″x10″ on the tail adjacent to the tail spring attachment points inside the frame. I’m hoping I can use the SS glue to secure the fabric, heat to shrink and then finish.

When Rans built the airplane they used automotive paints for top coat.

I’m wondering what the steps will be to finish mine.

Dan
Reno Nevada

[Andy Humphrey]

#12925

Dan,
Yes, our glue will work very well on that. Just scuff sand where you need to glue to. We would recommend sanding through the topcoat to the primer and glue to that for best adhesion. Sometimes if you glue to an automotive topcoat, it might crack and peel off with the patch. (on a certified aircraft it is required to remove the topcoat where the glue joint is) Once the fabric is glued on and shrunk, brush one cross coat of EkoFill into it, then brush or spray two more cross coats of EkoFill. Sand it smooth and feather it out onto your existing paint. Then you can paint over it with the original topcoat. If you need a white base under it for a lighter color topcoat, use E7510 EkoPrime. One cross coat is usually enough.

Thanks for using the forum!
Andy

[Kiwicubber]

#12978

Hi Andy, thanks for information above. We need to repair our Cub fabric, due to a crack in a longeron in the area of the horizontal stabiliser root that needs welding. We used Stewart system fabric and paints about 4 years ago.
Do you have any guidance about removing glue as necessary, or any other advice about our repair.

Cheers Bill Henwood
Te Kowhai
New Zealand.

[Larry Ross]

#13067

Wow, this answers the question I was going to ask almost exactly. I have some patching to do on an aircraft that had SuperFlite system put on it (I think) 7 or 8 yeas ago. It has been stored so weathering is not a problem, but some hangar rash is. The wings were a different color (Yellow) then re-painted white. The fuselage is all covered for the first time. The wings have a puncture or two, the worst is roughly T shaped and about 4X6″ – I am thinking about a larger patch basically rib to rib in that bay. Does that sound like too much? Owner doesn’t want it to look like a patchwork quilt. The fuselage (Ridgerunner III) has a large tear in the side from transport and I plan to cut out the loose fabric and run the patch to the surrounding stringers and longerons with a two inch tape at the edge for a perimeter (basically over the tapes that already cover those tubes). I just wonder if that sounds like too much or too little.
The videos are great, very informative, and I looked for one on patching but couldn’t find one. One last question is, when using the Ekofill, how far beyond the patch do you brush it for feathering? just an inch or so?
Thanks, Larry

[Andy Humphrey]

#13070

Bill,

The best way to remove our glue is with our glue eraser, or similar. The old glue will rub off pretty easily. If you do not have one of our erasers, all they are is a Harbor Freight sanding belt cleaning stick. We cut them into little pieces, but you can also use the whole stick. Another option if you have a larger area, 3m makes a decal remover wheel that can be chucked up in a drill and will spin it off pretty easily. You can usually find that at a local auto parts store or Amazon.

Andy

[Andy Humphrey]

#13073

Larry,

With Superflite, just sand down through the topcoat and glue to the primer and it will hold good. You can go from rib to rib. Just pull the old finish tape off and make sure you have at least a 1″ glue joint past the rib. You will probably need a 3″ tape to go over it and cover it properly. I’m not sure what you have for rib stitching, or if this is on the top or bottom of the wing. I’m guessing that one is probably riveted? If so, that makes it easy. If you are doing the top of the wing, just wrap an inch of the old fabric around the rib and glue it. Then drill out the old rivets, glue the patch over it and burn the holes through with a soldering iron and install new rivets. In any situation, make sure you have the minimum overlap joint of 1″, or on a trailing edge of the wing, 2″, and the leading edge of the wing, 3″. I normally take the EkoFill out 1-2″ to feather it out. Don’t forget to use EkoPrime white if you need a white base. Whatever was done on the original, try to do the same as close as possible so the final color matches. For example, if they painted yellow over silver or EkoFill and you use white EkoPrime, your yellow might be prettier, but it won’t match. When you get to painting, one little trick you can use is to cut masking tape with rotary pinking shears and mask your lines with that. Put the pinked tape on last and fold up a tab on the end. As soon as you are done painting, pull the pinked mask up so the wet edge will lay down and when it’s dry it will look like a tape edge. Much easier than blending. After about 12 hours, pull up the rest of the masking to see if you had any overspray penetrate the masking. If you did, you can remove it with lacquer thinner up until about 24 hours after application. From then on, the only way to remove it is sandpaper! Let me know if you have other questions.

Thanks!
Andy

[Brett Schooley]

#14127

Hello! I am a proud new plane owner which is covered with your system (11 years ago) and need to do my first patch job. I had to repair a bent trailing edge on the elevator which required a 3” long slit to be cut for access. The cut was placed an inch from the trailing edge with the plan to use 2” tape, giving 1” of tape on each side of the slit. I read the repair instructions and have a good idea of what to do. I also have an A&P guiding me through the process. The one question I have is that the finished fabric in the area of the repair, on both sides of the elevator, is a bit loose and has a few minor wrinkles (an area of about 1/2 square foot). I was advised to make the repair and after heat shrinking the patch per the instructions, if there is still wrinkles in the local fabric, to carefully use heat to tighten it back up. My only concern is that this fabric is finished, painted with your epoxy paint. Can I do this? Will the fabric tighten anymore now that it’s finished? Will the paint be damaged? I plan to paint the patch so I don’t mind if I have to paint a bit more, but just want to know what to expect and what the best route would be. Thank is in advance for the help!

[Andy Humphrey]

#14128

Brett,

You may want to use a wider tape so you can come around the trailing edge and still have the required overlap.  Your A&P is correct, you can apply the patch and shrink it and if you still have loose fabric, you can shrink it with the coatings in it.  That is one unique feature of our system.  You may want to use the sock on a small iron and keep it moving, slowly, but don’t stop.  If you’re careful it should not hurt the finish.  I would start at 250°F and only go higher if you need to.  We have a repair kit if you need to purchase materials.  That would be the most economical way to do it.  If you have to remove any fabric, I would love to have a piece of it for testing just to see how it’s holding up after all that time.  It’s not very often that someone has to remove our fabric that has some age on it.

Thanks!

Andy

 

[Brett Schooley]

#14131

Andy, thank you so much for the reply and the tips! Such good news that I can get this repaired. As far as the tape size, I was under the impression that I only need 1 inch of overlap on each side of the cut. Is this wrong? Sorry to say that I won’t be removing any fabric for this repair, but if I ever have to in the future, i will send it your way! Thanks again.

[Andy Humphrey]

#14133

Yes, you only need one inch minimum on all sides of the cut.  But if you cut is 1″ from the trailing edge, that would put the edge of the fabric right on the edge.  It would be undesirable to have a fabric edge right on the trailing edge.  You don’t have enough space to make it shorter and still have one inch, so the best thing to do would be to wrap it around the trailing edge a bit.  That was my thought.

 

[Brett Schooley]

#14134

Andy,
Ok, that makes sense. I see that I should have made the incision a bit further away from the trailing edge to keep it all on the underside. Oh well, I will use a larger tape and wrap it up over the trailing edge. Thank you for the advice!

[Brett Schooley]

#14136

Hi Andy,
One last question… the repair instructions state to heat the repair over the hole/tear first, then shrink the edges. I have also watched the videos where the finishing tape on leading/trailing edges is heated on the leading/trailing edge first, then heat shrunk outward. I assume I should still follow the repair instructions and heat over the cut first, but with my repair going over the trailing edge, will I have any issues heat shrinking outward from the cut over the trailing edge, or will it be fairly straight forward? Thanks in advance, I really appreciate the help and quick response. You guys are great!

[Andy Humphrey]

#14141

You will not normally shrink a finish tape, only if you need to form it around a curve.  If you have any bare fabric on your patch, that it what you want to shrink primarily.  The part that is glued down we would not need to shrink.  It is a good practice to use heat and firm pressure around the pinked edges to make sure they lay down tight.  But you are not really trying to shrink it.  If you still have loose fabric you can work at shrinking even the old fabric if it’s our system.  It should tighten up even with coatings in it.

 

Andy

 

[Brett Schooley]

#14142

Andy,
Ok, thank you! If I have this right, I will be using the fabric from the repair kit I ordered, not the finish tape since I will need a 3” wide by 4” long patch. My understanding is I will glue this patch on over the cut I made, providing 1” coverage on the inboard side of the cut, and the remaining 2” will wrap around the trailing edge. Gluing all of the patch on with no bare fabric, I then use heat and firm pressure on the edges. Any remaining loose pre-existing fabric I will then shrink carefully…

[Andy Humphrey]

#14144

Yes, that sounds right.  Let me know if you have any questions.  You can post pics on here as well if that helps.

Andy

 

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