RVG8tor

RVG8tor

Well Known Member
I have used Sika to glue on the canopy, I drilled about 7 holes to use clecoes to hold the canopy while fitting. The clecos allowed me to get the canopy back in the same position each time after removing for trimming. The canopy is glued and I like the fit, but in fitting the skirt I must have been a little rough putting the cleco in an out of this hole. I now have what looks like a chip on the inside of the Plexiglas (glued side), I plan to Sika the upper edge of the skirt but have been using the 7 holes in the fitting of the skirt. Not sure what to do about this chip area, I can try to drill it out to a larger size but then I will not be able to debur the hole. It will not get a rivet so it should only have the stress of the heating and cooling and the Sika will give during that.

So any ideas, drill out, or just leave and keep an eye on it. Inject epoxy in there to fill the void around the chip like they do with windshields? Silly that I go to the trouble to glue the canopy then make my own stress point!

Thanks for any input.

In the picture I have a flashlight on the are so it stands out better. The hole is 3/32

2v29zeq.jpg
 
Blend out the damage

Hi Mike,

I'd suggest blending the chip area using wet and dry until you get a nice smooth finish at around 600 grit, you could also drill the hole out to a bigger size if it's not being used or seen..

Cheers,
 
chip is on the inside

RV6AussieNick said:
Hi Mike,

I'd suggest blending the chip area using wet and dry until you get a nice smooth finish at around 600 grit, you could also drill the hole out to a bigger size if it's not being used or seen..

Cheers,
Click to expand...

The outside is smooth, the chip is on the inside of the canopy where the glue is located. There is a space between the canopy frame and the canopy where the fillet of glue is, I think what happened is the cleco came loose from the metal frame and snapped back and this hit the inside edge and chipped it. I could grind down from the outside until I get through to the glue layer and just shave it all down but I don't know if I would be cause more stress areas since I can't really deburr the edges. Looks to me like if a crack were to start is would more than likely move down but I am not sure.

Mike
 
Abrasive

Mike,

How about using an abrasive countersink, or any dremel like abrasive cone to grind down (slowly) and remove the stress crack, then fill the hole with epoxy. This would negate the need to deburr after drilling.

Don
 
Mike go to tap plastics http://www.tapplastics.com/ . I think they have a product called WELD 4. sounds like this might be a good answer to our cracks. Its not a glue. It welds the two halves together by making the plastic one piece again. Try the search engine here at Vansairforce. I think a few people have used the Weld 4.
Ron
 
I am new here and in fact a 1st. post but I have a 30 years of experience in plastics and can attest that the Weld 4 solvent based glues do as advertised and is the same company we buy our products from for production assembly.

Thanks for humoring a new guy on a tech. thread but I thought I had a little to offer.

Doug...
 
Welcome Doug...

I'm not sure we've had anyone else with 30 years of plastics experience and for a first post to help technically is great!:)

Again, welcome,
 
Thanks

All good ideas, that is what I love about this site you guys are coming up with stuff I have not thought of now I can do more research an choose a course of action. By all means please keep the ideas coming.

@Doug,

Welcome to VAF, nice to have someone with your kind of experience, you may have some great incites on how to deal with canopy cracks.

Cheers
 
read the specs on the glues etc.

I have cracked the odd piece of plexi over the last 25 years also.....just be sure to read the tech sheets on the different adhesives. While Weld-On 4 will surely penetrate, as it is 'water-thin', you may also want to consider Weld-On #16; it is essentially acrylic made into a syrupy liquid by addition of a lot of methylene chloride. ( we used to make our own by dissolving chips in a coke bottle!)
If you can squirt this into the hole, it will fill the void and harden around the chip, and possibly result in a stronger repair, closer to the original material.
 
Crack in Plexi

Hi Nemo
Don't feel bad ..I did the exact same thing with my new canopy on my RV-4..
Decided to glue it on using SikaFlex to help prevent potential crack but used 4 screws to hold it in place ( oversized the holes etc...) but ended up with a very small crack ( Could feel it only on the inside ) just above one of the screw..
I drilled it out and used WeldOn 3 to glue it shut...The crack hasn't expanded yet ( fingers crossed..)
WeldOn 3 works really good but be very careful when using it as it is very ''liquid'' and will dulled your plexi if you dropped some on..

Good luck

Bruno
[email protected]
 
FAR part43 has as its repair procedure using Weldon. In fact drilling the hole to the size of a plexi rod, soaking the rod in Weldon, inserting and finishing may solve your issue. I finish all my drilled holes with a soaking in Weldon. Seems to melt all potential cracks.
 
agough277 said:
FAR part43 has as its repair procedure using Weldon. In fact drilling the hole to the size of a plexi rod, soaking the rod in Weldon, inserting and finishing may solve your issue. I finish all my drilled holes with a soaking in Weldon. Seems to melt all potential cracks.
Click to expand...

That sounds like a good idea. Which number Weldon did you use?
 
Bruno ,
I was up at tap plastics couple of weeks ago and the manager said to use Weld #4 and not 3 only because #4 dries clear and #3 does not. If you have a drop get away from you do not touch it he says. It dries clear with a little shadow maybe. The cool thing was that he demoed the two products. I hope I don't have to buy the stuff!

Ron in Oregon
 
I wondering if you could just drill the hole to a #27, I would take two bits a #30 and #27 and file off 5% of the shape edge on each bit, and then drill through with the #30 first, and then #27. They should just burn through the plastic.

I'm not sure from the picture how far the crack goes out from the 3/32 hole. So use your own judgment. Good luck.

Jim
 
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