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sikaflex application question

Adam W

Well Known Member
hello

im just about ready to adhere the canopy to frame with the sika products. many of the posts here have been so helpfull im just about cumfortable with the process
i wasnt able to find the posts by Dan Horton for some reason
my last question i think is the following

once if sanded the surfaces, wiped on and off the 205, and then painted the 209 what is the method of applying the bead of 295
i know i have to use my spacers.
the question is do i lay a thick bead down on the frame and then lower the canopy on to it and when clamped the bead will take on the tringle shape they refer to?
or
do i clamp the entire canopy to the frame and then from the side try and squeeze in a bead of 295 that wil fill in the gap between frame and canopy and probably also form a nicer first round filet?

any help would be appreciated
 
I laid a good bead on the frame surface, then set the canopy in place which squished the adhesive around, mostly filling the space. I squirted another good bead on the canopy's outer face before attaching the aluminum side skirt. I then squirted more adhesive into the spaces to fill any gaps between the frame, canopy, and side skirt. You want the space filled with adhesive, but wipe off any excess to get a nice edge.

I drilled #40 holes through the frame, spacers, side skirt and the canopy edge, and used silver clecoes to hold it all together while the adhesive cured. Clamps will do the same for you.
 
Either way works...

I did this:
-prepare canopy and frame (fit, clean, sand, prime, .....)
-put masking tape or electric tape on the canopy (inside and out), the airframe, everywhere you want the sika-seal to end
-clamp canopy with spacers to canopy-frame
-apply sika in ?spot-welding? way to firmly fix the canopy in place/position
-let it cure (close the sika container airtight)

-remove spacers
-apply sika in the gap from both sides
-whipe excessive sika of with a custom scoop which forms the sika-bed you want
-pull off the tape
-let it cure

-let it cure some more
-resist the temptation to touch

-repeat last two steps for 2 days

Done!

You got yourself a perfectly bonded canopy.


Success!!!
 
If you look end on to the nozzle and imagine what a triangle looks like, that is how to trim it - edge on, it means a trim from both sides and a bit of a flat bottom. If you experiment with a cheap filler or silicone, try a small cut, get the shape OK in filler and then choose the size of triangular fillet you need.

Spacers..... Never used them and done 3 canopies, auto windshield companies don't use spacers - they just gun it on and stick it down ! The idea is that you set the canopy onto the bead and clamp it, then leave it.

Remember, the Sika only sticks to the primer, everywhere else it will roll off like cowgum.

Mask off with good tape - 3M Blue Platinum is their new product and is excellent - check Canadian Tire for it. If you use a tongue depressor, it is about the right size and shape for the bead on the second pass. Mask off just inside where the tongue depressor touches the canopy and you will end up with a good fillet.

Once the first lot of Sika has gone off - preferably less than 12 hours change the nozzle to a round end of suitable size and pipe in the Sika as smoothly as you can - just enough, not too much. Hopefully, one pass with the popsicle stick will leave a most excellent fillet but once done, remove the masking tape carefully and it will leave a super neat edge with very little thickness -

NOW LEAVE IT ALONE !

You don't need to mask the frame, but if you want to, you can - it won't stick.

If you want photos - PM me off line with an email address.
 
If you look end on to the nozzle and imagine what a triangle looks like, that is how to trim it - edge on, it means a trim from both sides and a bit of a flat bottom. If you experiment with a cheap filler or silicone, try a small cut, get the shape OK in filler and then choose the size of triangular fillet you need.

Spacers..... Never used them and done 3 canopies, auto windshield companies don't use spacers - they just gun it on and stick it down ! The idea is that you set the canopy onto the bead and clamp it, then leave it.

Remember, the Sika only sticks to the primer, everywhere else it will roll off like cowgum.

Mask off with good tape - 3M Blue Platinum is their new product and is excellent - check Canadian Tire for it. If you use a tongue depressor, it is about the right size and shape for the bead on the second pass. Mask off just inside where the tongue depressor touches the canopy and you will end up with a good fillet.

Once the first lot of Sika has gone off - preferably less than 12 hours change the nozzle to a round end of suitable size and pipe in the Sika as smoothly as you can - just enough, not too much. Hopefully, one pass with the popsicle stick will leave a most excellent fillet but once done, remove the masking tape carefully and it will leave a super neat edge with very little thickness -

NOW LEAVE IT ALONE !

You don't need to mask the frame, but if you want to, you can - it won't stick.

If you want photos - PM me off line with an email address.

Mike, are we talking about an inverted triangular cut into the tube tip with a flattened tip point?
 
Sika Done

well the canopy is adhered (i hope) to the frame.
I guess ill know in a few days what type of job i did.

thank you to everyone for your tips
 
Mike, are we talking about an inverted triangular cut into the tube tip with a flattened tip point?

Hard to describe, but sort of - you pipe a triangle with the base on the frame and the tip where the canopy will contact and squish.

Slice the end off the tip so the diameter is now the desired width of the fillet.

Now put a dot where the base line of the fillet is going to be, on the other side of the tip - what will now be the triangle apex, come back about 3/8" and with a sharp scalpel, NOT a Stanley knife :eek: cut from that point to each corner at the front on the base.

You should now pipe a triangle.

Get some ALEX or cheap stuff from HD and a couple of spare tips. It will take 2 or 3 tries and you will suddenly go...... Ahhhhhh !
 
Hard to describe, but sort of - you pipe a triangle with the base on the frame and the tip where the canopy will contact and squish.

Slice the end off the tip so the diameter is now the desired width of the fillet.

Now put a dot where the base line of the fillet is going to be, on the other side of the tip - what will now be the triangle apex, come back about 3/8" and with a sharp scalpel, NOT a Stanley knife :eek: cut from that point to each corner at the front on the base.

You should now pipe a triangle.

Get some ALEX or cheap stuff from HD and a couple of spare tips. It will take 2 or 3 tries and you will suddenly go...... Ahhhhhh !


Exactly what I was picturing Mike. Will look into what "ALEX" is now.

Thank you!
 
Deep breath, here we go

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sika flex

the short answer to your question is to apply a bead between the spacers and pull down (clamp) the coanopy to the correct thickness per instructions from Sika Flex (i think it is 3/8 Inch). You can then add additional Sika Flex up to the spacers and smooth with various curved objects (D batteries, fingers, popsicle sticks...). dipping the tool or finger in soapy water provides for a smooth finish. I recommend an article written by Pete Howell in the MNB RV Flyers archives that has a complete description and lots of photos. I have glued canopies on both the planes <i built and several I have assisted with.

Good luck
 
Pete Howell

...I recommend an article written by Pete Howell in the MNB RV Flyers archives that has a complete description and lots of photos...

Anyone know where this article resides? Google can't find anything. I would love to read it.
 
OMG..........

It worked :D:D:D:D

That isn't Sika, it is fireseal, but it is cheap and you get the idea.


Thank you for the effort, Mike! I just noticed I had not subscribed to this thread thank goodness I found it again!

I was thinking it was a cut on both sides but see it now as only one.
 
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