Canopy Crack

[skippydiesel]

Hi,

Sonex Legacy 175 hrs, a few months short of 2 year since first flight

Did my pre flight. Taxied down to the Club House. Came back to my Sonex & saw a 50 mm (2 in) crack in the Canopy had just appeared.

Crack is almost exactly mid point, on the opening side, radiating perfectly straight up. Its so perfect, it looks deliberate.

What to do??

Should I drill a stop hole?

Perspex glue?

My last air craft had no cracks after 20 years, now this!!!

Any good instructions on how to deal with this problem? 😈

[Blueadventures]

Usually a very easy repair, take at least 2 hours but likely 4 hours and pretty much invisible, someone at your airfield or within 100kms would have done these repairs. 

[440032]

Consult FAA AC 43.13-1B

Chapter 3 fiberglass and plastics.

Section 3. Transparent Plastics.

3-24 Repair of plastics.

[skippydiesel]

Thanks 440032 - looking into your suggestion now.😈

[onetrack]

Skippy, did you know about this following Sonex canopy service/availability?

 

https://www.sonexaus.org.au/but-and-sell/for-sale/australian-made-sonex-canopies/

 

[onetrack]

And there's this following modification for Sonex canopies -

 

https://docs.google.com/document/d/1z01IFU3TZG-q1dtxzjAUgkD_JUyMqMiwJATMaQ1hnB0/edit?tab=t.0

 

[skippydiesel]

 

Has anyone  used any of the following adhesives, to make good a crack in a canopy;

• E600 Industrial Strength
• Scigrip Weld ON 16 Acrylic/Polycarbonate
• Goroilla Glue Epoxy
• Gorilla Clear Grip - Fast Setting
• Permatex Permapoxy 5 Minute Weld
• Permatex Clear RTV Silicone
• ZAP Thin CA Glue
• JB Weld Plastic Weld
• JB Weld Superweld Instant Adhesive
• Acri-bond 110 Acrylic Cement
• Bostic Hard Plastic
• Loctite 406 Instant Adhesive
• Acrifix 192
• Selleys All Plastic Glue
• Weld-on 3 Acrylic Cement
• TENSOL 12 Acrylic
• EVO-PLAS TC 731

Please make your  Perspex crack repair recommendation, based on actual experince.

My thanks . 😈

 

[skippydiesel]

18 minutes ago, onetrack said:

And there's this following modification for Sonex canopies -

 

https://docs.google.com/document/d/1z01IFU3TZG-q1dtxzjAUgkD_JUyMqMiwJATMaQ1hnB0/edit?tab=t.0

 

Thanks for both of your suggestions.

 

My canopy is almost new. Has no other cracks (at this time). I would like to try and extend its safe service life, if this is feasible.

Canopy replacement, after just under two years & 175 hrs, just doesn't bear thinking about.

I will contact Ian Linke about his Australian made canopy - bound to be a more durable product.

 

Q. Is SonexAus still operating - I tried to join about 3 years ago😈

[Moneybox]

Most plastics cannot stand compression at the fasteners. If the rivets or screws are excessively tight it’s likely to develop a star crack originating at the hole. 

[BrendAn]

8 hours ago, skippydiesel said:

Thanks for both of your suggestions.

 

My canopy is almost new. Has no other cracks (at this time). I would like to try and extend its safe service life, if this is feasible.

Canopy replacement, after just under two years & 175 hrs, just doesn't bear thinking about.

I will contact Ian Linke about his Australian made canopy - bound to be a more durable product.

 

Q. Is SonexAus still operating - I tried to join about 3 years ago😈

that link said he was out of stock in 2020.  you would think there would be an update in the last 5 years if he was still selling them.

[facthunter]

Cracks are caused by stress Points. Nev

[skippydiesel]

Found this;

ULRICH NEUMANN

25 Dec 2000, 07:23:42

 

Several years ago, I had to repair a crack in my Libelle's canopy. Acrifix

works well - I let it cure by the window.
But just smearing Acrifix over the crack looks horrible. I think the main
thing about crack repair is the preparation of the seam. Here is how I did
it:
1: Place a 2" wide clear plastic tape over the crack. This will protect the
canopy's area to the left and the right of the crack during the following
operations.
2: Drill a 1mm hole at each end of the crack to keep it from propagating.
Caution: examine the orientation of the crack. It may not be perpendicular
to the surface, so the hole may have to be drilled in an angle and be sure
to really catch the end. Otherwise, it may spread beyond the repair.
3: Using a Dremel tool and a small ball grinder (dia. 2-3mm), carve out the
crack to halve of the material thickness through the clear plastic tape.
4: Do not remove tape and clean 'weld-prep' area with rubbing alcohol.
5: Fill seam with Acrifix and let cure. Over-fill seam slightly since
Acrifix will shrink slightly as it cures.
6: Repeat procedure from other side of canopy. Be sure to carve into the
repair material of the first operation.
7: To remove eccess material, use file, fine wet sanding paper and buffing
compound.
8: Remove plastic tape and buff area with plactic buffing compound.

My canopy is holding up since more than 10 years now with minial optical
distorsion. Feel free to contact me, if you have any questions.

[skippydiesel]

FYI;

PlastiFix

• Aircraft Spruce $76.00
• JB Tools $50.00

😈

Edited yesterday at 12:16 AM by skippydiesel

[Blueadventures]

1 hour ago, skippydiesel said:

Found this;

ULRICH NEUMANN

25 Dec 2000, 07:23:42

 

Several years ago, I had to repair a crack in my Libelle's canopy. Acrifix

works well - I let it cure by the window.
But just smearing Acrifix over the crack looks horrible. I think the main
thing about crack repair is the preparation of the seam. Here is how I did
it:
1: Place a 2" wide clear plastic tape over the crack. This will protect the
canopy's area to the left and the right of the crack during the following
operations.
2: Drill a 1mm hole at each end of the crack to keep it from propagating.
Caution: examine the orientation of the crack. It may not be perpendicular
to the surface, so the hole may have to be drilled in an angle and be sure
to really catch the end. Otherwise, it may spread beyond the repair.
3: Using a Dremel tool and a small ball grinder (dia. 2-3mm), carve out the
crack to halve of the material thickness through the clear plastic tape.
4: Do not remove tape and clean 'weld-prep' area with rubbing alcohol.
5: Fill seam with Acrifix and let cure. Over-fill seam slightly since
Acrifix will shrink slightly as it cures.
6: Repeat procedure from other side of canopy. Be sure to carve into the
repair material of the first operation.
7: To remove eccess material, use file, fine wet sanding paper and buffing
compound.
8: Remove plastic tape and buff area with plactic buffing compound.

My canopy is holding up since more than 10 years now with minial optical
distorsion. Feel free to contact me, if you have any questions.

That's how I've done single and multiple joined cracks.

[facthunter]

Most earlier stuff was FLAT Perspex supported by a fairly strong frame  on 3 sides.. Nev

[skippydiesel]

Just got off the phone with Nick (working on a Public Holiday??) from Acrylic Technologies Australia Pty Ltd, who sell ACRIFIX.

 

Nick  recommends ACRIFIX 105 https://acrylictech.com.au/product/acri-bond-105/

 

ACRI-BOND 105 Acrylic Adhesive is the industry standard in bonding Acrylic (PMMA) to itself as well as other listed plastics. Fabricators use ACRI-BOND 105 when they want unmatched strength and bubble free joints. ACRI-BOND 105 is a solvent cement meaning it works by chemically softening and fusing the surfaces of compatible plastics. This creates a true molecular bond where the two parts effectively become one solid piece after curing. This provides a strong bond that other Acrylic Glues cannot achieve.

 

As this is a hairline crack, invisible at some angles, I think I will give this product a go

😈

Edited yesterday at 01:54 AM by skippydiesel

[facthunter]

Are you sure of what your Material IS?  Nev