Steve Ashby

Steve Ashby

Well Known Member
Sponsor
I am about to glue my 8A canopy (not to be confused with an 8 canopy, which is completely different :) using new Sikaflex, cleaner and primer. I caved into peer pressure to pitch the expired stuff.

I am using the popsicle stick method of spacing the plexi from the frame for the right gap to maximize adhesion. I drilled through the plexi, through the popsicle sticks and into the canopy frame so that I could cleco the canopy onto the frame.

Here is my question: When I glue the canopy onto the frame, will I have to do something to the popsicle sticks to keep them from sticking? I will have to pull them out after the Sika dries and I am concerned that the popsicle sticks might not pull out cleanly (or even break off).

For those who have glued before, what is the deal?

Thanks a million!
 
Here's how I did it....

Hi,

So, here's what I did. On the first application of the Sikaflex, just put it inbetween the spacers, down in the gaps and partially fill the area, but do not build up the full fillet. You just want to get enough to get a good bond. Do not put any Sikaflex near the spacers.

Now, wait one day. If you can cover everything up with a light drop-cloth to keep dust out of the area, that's good.

OK. After 24 hrs, the first application is cured. You now pull the cleco's out, and the spacers. They will come out clean, because you did not get any Sikaflex on them. Now, you can fill in the gaps where the spacers were, and then proceed to build up the nice fillet of material that you will screed off with a radiused tool ( I used tongue depressors).

This process lets you make one nice smooth fillet all at once. Resist the temptation to build up any of the fillet on the first day.

Lots has been discussed about the guideline that the Sikaflex should be put on the primer in the window between 2 hrs and 24 hrs. and whether more primer needs to be added after waiting 24 hrs. I found in the Sikaflex literature that the primary concern was dust accumulation, not any aging problem of the primer surface. I found in tests, and in my actual canopy, that the adhesion to the primer is perfectly normal when applied after 24 hrs. Indistinguishable from the bond from application at 2 hrs. So my advise is not to worry about that.

Good luck,

Steve.
 
I used small sections of nylon garden hose (1" or so in length) split lengthwise and 'wrapped' around the canopy frame tube on my RV6. Applied the first bead of Sika to hold everything in position. When cured the garden hose spacers came out relatively easily and the resulting gaps were easily filled when applying the finishing beads on either side of the tube. Worked like a charm.

Clive Whittfield
Auckland
New Zealand
 
Steve:

I have no useful information to provide because I didn't glue my canopy on, but it sure is good to see you back on your project!

- Jamie
 
"O"ring spacers

"I am using the popsicle stick method of spacing the plexi from the frame for the right gap to maximize adhesion. I drilled through the plexi, through the popsicle sticks and into the canopy frame so that I could cleco the canopy onto the frame."


I did something similar to this but used small diameter "O" rings.
I drilled through the plexi and the frame like you mentioned for location purposes and placed "O"rings between the plexi and the frame held in position with clecos.
The "O"rings remain in the assembly with the Sikaflex.
 
dpansier said:
"I am using the popsicle stick method of spacing the plexi from the frame for the right gap to maximize adhesion. I drilled through the plexi, through the popsicle sticks and into the canopy frame so that I could cleco the canopy onto the frame."


I did something similar to this but used small diameter "O" rings.
I drilled through the plexi and the frame like you mentioned for location purposes and placed "O"rings between the plexi and the frame held in position with clecos.
The "O"rings remain in the assembly with the Sikaflex.
Click to expand...

I vote for O rings. So much info in here!
 
Yet another suggestion... I started by making spacers cut from vinyl tubing. Used different wall thicknesses so I could shim appropriately, since the slider bow for my 7 was, shall we say, less than perfectly formed.

Then I saw a suggestion by someone who had made spacers from the rubber tubing used to hold screen in a screen door. He cut short sections from it, then used superglue to hold them to the frame. Then applied primer and 295UV over them, leaving them in place.

I decided to do a variation on the same theme, only since I needed varying thickness spacers, I just cut little squares out of the tubing sections I already made. Stuck 'em on with superglue, primed, applied Sika, etc.

Several weeks later I had the "opportunity" to learn how well the Sika had adhered to my spacers when I joined the Cracked Canopy Club by dropping a pair of vice-grips directly above where the pilot's head would be. I used a razor blade to slice the Sika and get the cracked canopy off, so I could re-use the frame. Using pliers, I tugged on stray pieces of Sika in places where I knew I had spacers. Some spacers pulled loose from the canopy frame, taking gray powder coat with them. Others ripped in half. I didn't see any evidence of adhesive failure (Sika pulling off the spacer, leaving the spacer intact). Based on what I saw I don't believe that leaving small spacers in place results in compromised structural strength, though obviously it could take years before that becomes apparent.

When I did Canopy 2.0, I used the same technique. Saves a little time since you don't have to go back and fill in after removing spacers.
 
Back on project...yeah

Steve,
I second the motion of "good to see you back on project". I met you in Evergreen shortly after I started my 8A and you loaned me tools to back rivet my wings. Seems like a long time ago. My "I can finish in three years" will have doubled by the time i actually do. Oh well life gets in the way. Press on.

Tim Pethel
 
Steve, I used the water hose ring

method to maintain a constant distance space between steel frame and canopy plastic. Know it is easier to go wider with the primer then marginal. Be sure to rough up the surface with at least 100 grit before cleaning and primer. Also let it cure very well before removing clamps and spacers. I have seen impatience here and it was not pretty. Let it cure a couple days as it is getting cooler. Use warm soapy water to smooth out the surface with finger. Have a bunch of rubber gloves laid out for quick and easy change as your applying the gue. It is a mess far beyond proseal. Also get a big strong chalk gun.The tubes are tough to push out. I would have a spar gun just in case the first one breaks. Ask me how I know. Also, be sure to mask the inside of the canopy as well as the out side. The silka will come off pretty easy from the plastic surface. What will not budge it dried primer. Last, if you'd like to see my finished RV-8a canopy your welcome to visit my hanger in Thomaston. I'll even let you see me takeoff and fly around to inspire your effort. I got just such a boost from visiting your basement shop years ago when you hosted a get together when you finished your wings. Call me for visit at 478-731-9678. Good luck, Bill Phillips
 
WHAT FANTASTIC ADVICE!

You guys are the greatest. Don Pansier's tip about the O-rings sounds like a great plan. I stopped by the Handy Hardware (that's really its name) on the way to work this morning and got a handful of O-rings, so I should be ready to roll.

All of the other tips are also extremely helpful. I plan on a visit to Home Depot to get two (one and an e-bus spare) heavy dooty caulk guns, as well as another box of rubber gloves.

One other question. I thought about laying a bead on the frame and then setting the canopy on it. Would it be better to do it that way, or to cleco everything together and then caulk the Sika in with everything already together?

Thanks again for the help!
 
Steve, I offer this

I have glued two RV-8 canopies. I used two saw horses in a T formation as a work stand to secure the frame and canopy and offer good access under neath to the work areas. I used long wood screw with washers in a stack spaced exactly the width of the canopy connectors for the canopy frame tubes to set on and a block rased up to represent the turtle deck heigth in the rear to have three points of control and to hold the frame steady. You want it set level and just like it will be on the plane. Then you set on the floor and fill in the gaps with black gue. I would send you a photo if I can find one. Good luck, Bill Phillips
 
Steve Ashby said:
You guys are the greatest. Don Pansier's tip about the O-rings sounds like a great plan. I stopped by the Handy Hardware (that's really its name) on the way to work this morning and got a handful of O-rings, so I should be ready to roll.

All of the other tips are also extremely helpful. I plan on a visit to Home Depot to get two (one and an e-bus spare) heavy dooty caulk guns, as well as another box of rubber gloves.

One other question. I thought about laying a bead on the frame and then setting the canopy on it. Would it be better to do it that way, or to cleco everything together and then caulk the Sika in with everything already together?

Thanks again for the help!
Click to expand...

I set the frame into the canopy, then started caulking. I aggressively squirted the Sika between frame and plastic in the hope of not getting voids. Again, mine was a 7, and having not Sika'd an 8 frame it may be different enough that that isn't practical. In any case, when I cut off the canopy due to my previously described moment of stupidity, it turned out to be void-free, so my technique worked. Just one data point...
 
What is the name of the product and Where do I buys it?

Gentleman, I am thinking about this as well. Sikaflex? What type, do I need a primer/cleaner? Spruce, Jamestown Distributors, where buy?
 
I got mine from Jamestown. There are pretty good docs on what cleaner & primer to use. There are also instructions on UV protection of the joint (black paint).

Charlie
 
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