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dbc

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Reply with quote  #51 
The cross bar clips are an off-the-shelf item available at Home Depot, and probably elsewhere.  They are really easy to use - you just push the square part into the end of the crossbar, and the hooked part fits right into the spline groove of the frame.  The cross bar is the same material as the rest of the frame.  The clips don't grip the main frame side very well until you press in the spline (or sisal rope in my case).  The spline locks the clip in place, and the cross bar just becomes part of the frame.

I didn't have much luck trying to copy a picture, but The following link should take you to the HD site.  I am also sending a link for the self-drilling sheet metal screws I used on teh corner braces.  HD used the same picture is the same for several different screw lengths; my screws are shorter than the one shown.  I will take a picture with my phone tonight.

http://m.homedepot.com/p/5-16-in-x-5-8-in-Crossbar-Clips-10-Pack-3022444/202091976?keyword=Screen+cross+bar+clips&searchtype=text

http://m.homedepot.com/p/Everbilt-6-x-3-8-in-Zinc-Plated-Pan-Head-Phillips-Self-Drilling-Drive-Sheet-Metal-Screw-100-Piece-801012/204275116

gbwillson

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Reply with quote  #52 
Thanks Don-

I'll let him know those clips are off the shelf at HD. I'm sure he'll consider them for any future screen cross bracing. I know I'll be using them in the future.


Greg in MN
stmbtwle

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Reply with quote  #53 
Good to know!

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Willie, Tampa Bay
gbwillson

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Reply with quote  #54 
Great! No wonder I've never seen these before. I just checked and these clips are not available within 100 miles of me. So sad...[frown]

Greg in MN
stmbtwle

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Reply with quote  #55 
Also called "screen spreader bar clips", Amazon, Ebay, and several others have them.

Might also use small "T" brackets.

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Willie, Tampa Bay
dbc

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Reply with quote  #56 
The clips are made by Phifer, if that helps.  Here are some pics of the hardware I used on the screens.

The clips are just thin aluminum.  I guess you could 'forge' some from scratch with a square form for the body and a nail for the hooked part.  Never tried that, but I can hammer one flat and measure the piece.  May have to someday; I see the local store only has 1 bag left.

IMG_0904.JPG 

IMG_0905.JPG 

IMG_0906.JPG 

gbwillson

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Reply with quote  #57 
Nice to know what these are called Willie. Here is a link to the clips on Amazon. 

https://www.amazon.com/Prime-Line-Products-PL-7794-Spreader/dp/B000BQPWBK/ref=sr_1_1_m?s=hi&ie=UTF8&qid=1471037527&sr=1-1&keywords=Spreader+Bar+Clips

Although Home Depot didn't have them nearby my location, it doesn't mean they can't be found locally at any of the big box hardware stores or your neighborhood hardware store. It's nice to see photos too, since trying to describe this item to someone can be confusing if you've never seen it before.

As Don suggested, you could make these out of a scrap of heavy aluminum or galvanized flashing. Don, if you flatten one of the clips out, take a photo of it next to a ruler and post it. They look easy enough to make and you don't need very many. Heck, a cut out scrap of flashing and a pair of pliers would be all you would need.

Another thought, since Don had already used the corner braces, would be to use T-Braces or more of the flat corner braces to attach any cross bracing. But as he mentioned, it may make assembly slightly more difficult. And if you are really on a budget, using a small scrap of heavy flashing will work fine too.

Greg in MN




dbc

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Reply with quote  #58 
Here are a couple photos of a cross bar clip flattened out.  These things are pretty crude.  Looks like a little less than 1 inch square:

Clip, flat 01, 081316.JPG 

Clip flat 02, 081316.JPG 

2 clips, 081316.JPG 

I thought about using T-braces on the crossbars, but eventually abandoned the idea in favor of the clips.  At first, I was thinking in terms of 'helping' the clips, since they don't grip the main frame very well when you first install them, although they do fit quite tightly into the ends of the crossbar.  I squeezed the hook part on one clip, but that didn't help either, and actually made it not sit right in the spline groove.  Finally I realized the clips don't need to grab the frame.  They just need to hold the crossbar in position until you press the spline over it.  That's what really holds it; the tightening screen pulls the main frame tight against the end of the crossbar, keeping everything in a single plane.  Simple but brilliant.  You just set the cross bar in there and make final adjustment right before you push the spline over the clip. 

One question with T-braces is which side to put them on.  This came up when I was considering the same question for the corner braces.  I thought it would be good to install the corner braces before the screen to help keep it square.  The corner braces are outside the spline groove, so I put them on the front, so the frame would lay flat on the table when I put in the screen.  You couldn't really put T-braces on the front before the screen, because they would cover part of the spline groove.  If you do them after, the screws would have to penetrate the screen, and besides, the crossbar needs to be there in there beforehand to do any good.  You could put T-braces on the back, but then the frame would rock on the brace when you were installing the screen.  Even if the corner braces were also on the back, the frame still wouldn't lay completely flat, without using a bunch of shims, etc.  I finally decided T-braces were more trouble than they were worth, since the clips worked so well by themselves.

The other problem with all the braces is that the screen frames are really thin metal, and they don't hold a screw very well.  The brace itself is 1000 times stronger than the attachment.  I am not sure the braces are doing much good.  They also make the screen want to pucker near the corners during installation, because the braces and screw heads stick up.  I would like to find something better.  At this point, I will be happy if the corner braces keep everything square and tight until I can join the front and back screens and get the whole thing inside the collector.  I guess the other reason for corner braces is back-up for the plastic corners, which may weaken when heated.

Best solution I can see is to make some sort of adjustable temporary jig to surround the frame while you install the screen, which you could then do without using any braces.  Then, put the braces on afterwards, either on the back or on both front and back with screws going through both + the frame.  Better yet would be a metal corner reinforcement that snapped over the frame corner.

How I installed the corner braces was to clamp one long side of the assembled screen frame on a table, then loosely clamp one adjacent short side on the end of the table while checking for square.  I measured diagonally corner to corner, making fine adjustments until both measurements were the same.  Then I clamped the short side (carefully so as not to crush the frame), checked for square one more time, and installed 2 of the corner braces.  Then I repeated for the other two sides and installed the braces on the other end.  A jig would speed up this method too.

I have all 4 screen frames made already, with corner braces on top, but I do want to try adding 2 more crossbars to supplement the one in the middle.  I think that may be the best way to keep the frame from bowing inward.  Here are front and back pictures off the cross bar to frame juncture.  As you can see, the screen doesn't attach to the crossbar, just to the main frame.

Crossbar front, 081316.JPG 

Crossbar back, 081316.JPG 

stmbtwle

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Reply with quote  #59 
Good to know, thanks!

I'm thinking one might be able to use same concept to make internal corner braces.

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Willie, Tampa Bay
gbwillson

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Reply with quote  #60 
Nice photos and explanation Don-

If you used flat corner braces and T-braces and attached them to the side opposite the groove you would have at least 6 points holding up the frame to keep things level while attaching the screen. But as you say, that means the entire screen frame is sitting a little bit above the working surface, making it difficult to press down when installing the spline into the groove without added support. One advantage of the vinyl spline is you can stretch it to make it easier to install and it will expand when released. 

I wonder if you could reinforce the ends of the thin aluminum framing by stuffing a piece of foam an inch or into the frame ends and filling the ends with a fast-set epoxy? Or even make metal or wooden corners, instead of the plastic ones. I've never seen metal ones. But I bet you could fashion some out of some of those flat corner braces with a little bending and grinding. 

Greg in MN
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