Applying canvas without wrinkles ....

[GPW]

Any body having troubles with wrinkles ? There are ways to avoid them whilst covering ... we need to talk about this !!!

[GPW]

Hmmm??? Seems like nobody wants to talk about this
You guys ever hear of “on the bias” ...
Consider this ... we’ve all applied the canvas dutifully in the fore and aft fashion .... Right? Done so , only Half of the thread is doing the work ...think about it ... If we now apply the canvas “on the bias” , all the threads are working equally in load and the material becomes much more stretchy... Conforming easier to rounded shapes .. twice as strong , same weight ...

Just so you know .... ... without having to discuss it ...

[Lancie49]

That all makes sense Grant.
So what you're saying is to be sure and pull/stretch the canvas in both directions, along and across the roof as you are applying it.

That of course would open up the weave slightly and allow the adhesive or paint to penetrate deeper as well.

When I did mine I didn't go both ways and the finished painted surface has a leather like appearance.
I rather like it but next time we'll go for something smoother.

[GPW]

Lance, actually apply the canvas so it appears as a X rather than a + ... 45 degrees to the fore and aft ... I know , it may be a little more wasteful ... best hit the sales ... and it doesn’t have to be applied like that on the straight areas , only on the rounded areas ...

[Rosey]

I used a wallpaper brush to smooth the canvas on mine, it helped a lot.

[eaglesdare]

i had 4 people stretching canvas. we had no problems with wrinkles.
i could see if someone was doing this alone, that their might be problems with glue/paint/primer drying before one could stretch it out. i recommend having friends help with this step of the build.

[Lancie49]

Hmmm. more arms and legs for the next one me thinks............

[josephhanson]

Did anyone nail or staple the edges until the canvas was dry?
If so were the nail holes or staple holes a proplem?
I will probably be a one person show when the canvas time comes.

[GPW]

... and just a few words on those frayed canvas edges ... Tried Pat’s trick of using a very thinned glue painted on the lines before the cut ... used Elmers NON-waterproof glue ... the “theory” as applied to Foamies being that the little bit of glue will just melt into the adhesive and top coat ... sure cuts nice and no frayed edges ... works great on the bias too ...
Disclaimer: I did Not try this on a trailer yet , only on a canvas hat ... on a particularly loose piece of canvas which tended to fray all by itself ... Worked fine !!! Problem solved !!!

[eaglesdare]

ratkitty came over for the covering of the roof on the interior of my foamie. ( i just couldn't manage the positions right for that with just having surgery, body would not bend in those shapes needed. )
but we did in fact use a staple gun to hold the canvas up and in place for this part. it was not a warm day out so the glue was not drying fast. staples do help and have not caused "me" any proplems at all.

i do believe someone has mentioned using push pins to help with this. i tried those things and for me they were more of a pita than anything. would not stay in and well i stopped using them.

i can't imagine someone doing this process alone. not for a 4x8 (at least) section. by the time you got the glue/paint on it would be dry before you even put the canvas on. so i would suggest (this is from my own experience only) that you work in small sections at a time. precut the canvas to fit with a couple inches overhang. could cut overhang to 6 inches or so. have the over hang stapled to the roof part, then glue/paint the section of side wall, then lay/stretch the canvas. staple underneath, then continue in sections with glue/paint and stretching your canvas. the glue/paint will dry pretty fast if using in temps 60 and above.

if you do use staples though i would be careful with stretching too hard if those staples aren't shot into wood. i would also think they would pull out of just foam.

[GPW]

Joe , I did mine by myself , small sections at a time using pushpins and blow gun darts to hold one end while I glued and stretched it ... the holes just disappeared later under the primer and paint ...

Ps. I covered my insides before assembly .... Much easier that way .... it was difficult enough adding just the reinforcing strips on the inside ... that Overhead work ...AARGH!!!

[pete42]

when I covered my airplane with fiberglass we cut some of the fiberglass on the bias "they" said to do it so the fiberglass
would be stronger because the direction of the thread. I don't remember if it was the bi-directional fiberglass or the unidirectional fiberglass
what is the canvas fabric uni or bi-directional? I also used pinking-shears to cut the fiberglass made the ends less likley to unravel.

pete

[Wobbly Wheels]

Pete, with glassing you develop greater overall strength the more directions you have fibers running.
I'm guessing you alternated layers of 90 degree cloth with the fibers run fore-and-aft, then bias, then fore-and aft, etc ?
Unidirectional glass is used along the direction of pull ('lengthwise'): along the top and bottom of wing spars, maybe leading edges...anywhere that you want to resist or control a tensile load. Applying uni on the bias would be a waste of material unless that's the direction of the anticipated load.

I'm using epoxy and glass, so I can't speak to canvas specifically.
I'll be doing my second unit (layer) on the bias mainly because it will lay better over contours. There will be a significant increase in panel stiffness, but I'm already into the 'overkill' category with the weight of cloth I'm using. If you are only doing one piece, it's a bit more wasteful but with multiple pieces on the same bias angle your last cut becomes your first edge for the next piece. Of course, that changes whether you are cutting your pieces from a big square drop cloth or off a roll or bolt.
I'm using 38" wide cloth, so I'll have a triangle left at either end, but it won't go to waste. With glass cloth you can also skew the weave a little for difficult contours because the weave is so loose. I've not had the problems with glass cloth that some of you have had with wrinkles in your fabric, so I wonder if that flexibility might be the difference ?

Also with glass, you typically cut out darts where wrinkles would otherwise appear. If there's a slight gap from over cutting a dart, it's easy to fill it and still keep full structural strength - I'm not sure one could do that with fabric.

If someone has upholstery experience, I wonder how much you would gain structural strength by 'tailoring' the canvas over the foam rather than bonding and shrinking it ?
Actually stitch the side-to-roof seams before applying whatever paint, glue, lagging, etc you're using....more work for sure, but worth it in the finished product ?
One could leave the stitches bare and varnish them to get the IXI pattern of the old doped wood-and-canvas wings.

[GPW]

W2 , I also considered a sewn “sock” for over the foam ... You’d have to be Exact and still maybe just leave one end loose to allow for material stretch (unless you were really GOOD !!! ) ... like a big toaster cozy ... sorta’ ... Fitted properly , it would give the advantage of perfect seams , and would be very attractive/ pleasing to the eye ... appearing somewhere between tent and trailer ... all in the details ... No reason a foamie can’t look Cool ... I’m investigating some chrome trim from the auto parts store ... comes on a roll ,pretty inexpensive , just a little looks “trick” ... could protect the sides from careless car doors too ... “decorations”

More on this ... for a really lightweight Foamie , think about a tent attached to the foam , using tent-like window openings and screens, flaps etc. ... like Velcro on windows , waterproof flap above sewn into the “sock” ... things like that ... Bare minimum ... could even have a snap on , or Velcro interior sock ... with padding in all the right places, little pockets to hold your stuff ... you could even take it in and out later to wash it ... The foam merely giving the ”tent” it’s shape and providing insulation ... Simple but challenging ....

[eaglesdare]

that is what i used on the first foamie for my windows. i cut out the screen mesh from an old tent, and put them in (actually they are still there ) hey it works. then i used part of the nylon of the tent to cover the windows on the inside to prevent water from coming in. hey it worked also. wasn't pretty, but it worked.

i was just sitting here thinking about the new foamie. i want a front window, but i don't want a heavy one. so i was sitting here trying to think of a clear lightweight material to use. any ideas? plexy is a little heavy, but i will use it if i can't find something else to work. also that front window will not be an open window, just a space to look out, or have light come in.
oops sorry, this is a canvas without wrinkles thread.

ok back to topic....