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dlomheim

Well Known Member
I have read all I can find on using the SIKA product to secure my canopy to the slider frame. Before I jump in and do this I was wondering if some of you who have "gone before" could post some of your "lessons learned" or things you'd do differently the next time...

Thanks for your information.

Doug Lomheim
RV-9A; 90116
Finishing
 
I too, am very interested in this product!

I found this WIKI on the subject and have been noodling over it for the past week or so.

What I was wondering is, how do you get the stuff to tool down nice and flat like in this picture along the forward edge?

Forward_Sikaflex_fairing.jpg


I see on the tech sheet that there is a tooling compound or something, but I have never used anything like that before. What is the deal? How is it used?

Doug, good question! I am looking forward to hearing the answers!

:) CJ
 
Captain_John said:
I am looking forward to hearing the answers!

:) CJ
Click to expand...

Do a few searches on "Canopy Gluing" (and variations on that theme) and you will find that many of the answers are already here! This has been discussed a lot in the past.
 
My experience

You will find my thoughts here. Look at the May through June '07 entries.

It sands quite well if you leave it several days first. I guess that is how the shape was made in the picture on the second entry below.

You wont regret doing it that way.
 
What I was wondering is, how do you get the stuff to tool down nice and flat like in this picture along the forward edge?
Click to expand...
It is much easier to create a nice fairing with Sikaflex than with fiberglass. Just place 3 or 4 layers of vinyl tape above and below where you want the fairing and fill the area with Sikaflex. Shape the desired curve with a plastic bondo applicator. Don't worry about high spots; they can be sanded down with 120 grit sandpaper. The next day go back over any low spots until your satisfied with the final finish. Two or three "coats" filling and sanding will produce great results. You might want to use the Sika cleaner between coats, but not the primer.

Remember to paint the finished fairing with a water based enamel to protect it from UV. Do not use a mineral spirit paint...it will soften the Sikaflex and will not dry.
 
....not the primer?

Jim Ellis said:
You might want to use the Sika cleaner between coats, but not the primer.
QUOTE]

Jim - why do you think 'not the primer'? I have been puzzling about that and thought the other way around.

Thanks,
Click to expand...
 
Steve,

If you use the primer between "layers" as you build up the fairing it creates a discontinuity that doesn't sand well. The fairing is more cosmetic than structural away from the contact surfaces and a homogeneous application is easier to shape. Remember this fairing is created after the plexiglass and metal have already been bonded together.

The Sikaflex sticks very well to itself with no pre-treatment, but the cleaner or even isopropyl alcohol can be used to remove any dust or sanding residue that might be on the surface

Hope this helps.
 
Jim Ellis said:
Remember to paint the finished fairing with a water based enamel to protect it from UV. Do not use a mineral spirit paint...it will soften the Sikaflex and will not dry.
Click to expand...

Will a mineral spirit coating eat a fully cured Sika fairing?

:confused: CJ
 
Originally Posted by Captain John
Will a mineral spirit coating eat a fully cured Sika fairing?
Click to expand...

Mineral spirits seem to have a slight solvent affect on cured Sikaflex. It seems to soften the surface until the thinner evaporates. When a mineral spirit based paint is applied the paint stays semi-liquid and refuses to harden. Can't explain it, but it sure makes a mess.
 
I see.

Perhaps I will use the white stuff around the leading edge of the canopy rather than painting it at all.

On the tech sheet, it shows black and white for colors.

The rumor mill tells me that the white stuff isn't as strong, but I don't see how it could be. They share the same tech sheet.

:rolleyes: CJ
 
Thanks to Jim Ellis and others who have gone before, mine came out great! The day after the gluing I filled the voids left by the spacers and used a gloved finger to make a small fillet. I intend on using a small fiberglass fairing over it so I can blend into the side ears/skirt area. My advice is you will probably need 2 tubes of Sikaflex, but there is enough primer cleaner to do a minimum of 2 planes and still have leftover. I used exactly 1 tube on the front canopy. I imagine that it will not take a full tube to glue the aft window.


 
Fiberglassing over SIKA

Rockyjs said:
I intend on using a small fiberglass fairing over it so I can blend into the side ears/skirt area.

Are you planning on putting a strip of glass completely over your newly created SIKA "fairing" or just at both ends where it will transition to the side skirts? Do you know of any issues of getting glass to bond to the SIKA?

Thanks.

dl
Click to expand...
 
I'll probably do the entire fairing in glass. I just smoothed out the Sikaflex, and really didn't do much on it. I have tried to sand some on a scrap piece and it does sand nicely when cured. It is easy to work with. I had my 15 year old get inside and apply a bead along the canopy aft frame when we glued. I haven't tried to glass over it, but it shouldn't be a problem.
 
I am not an expert, but here is my 2c on my experience...

Use lots of tape to mask stuff off, 2 layers, like in the pdf, cause you will do 2 runs, one for structural, second for looks. A wet soapy finger makes good fillets. The sika reacts with the water so it skins quicker when you run your soapy finger over it, so make sure you get the "looks" run right in one or 2 passes. Make the sika where it meets the masking tape edge as thin as possible. Remove the masking tape immediately after your "looks" run, if the sika edge is thin enough it will leave a perfect transition line, otherwise it will leave an edge and a peel line.

It is hard to get a perfectly flat smooth look ala fiberglass, but you can get it as close as d@mnit, as good as any windscreen install in a car.

The transition from the front to the side skirts on my tipup is where I had most unpleasing results, cause the sika gets a bit thin there over a big area.

I want a perfect look so I am going to run 1 thin layer of glass over my sika, sand it perfectly smooth, then one can paint it with any paint you want over the glass.

Regards
Rudi
 
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That is the kind of detail I was looking for, Rudi!

I like the idea of the thin layer of glass covering it all, too!

Thanks All!

:) CJ
 
I drilled a few holes through the plexi and in to the steel to help position the plexi and so I could hold pressure during bonding. Remember to have the spacers in between the plexi and steel before drilling holes in the sides so they line up correctly. The bond line thickness is critical because of the different thermal expansion rates of the plexi vs steel.
 
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