Author Topic: GLASSING QUESTION: Can I overlap 2 short pieces of cloth when laminating deck?  (Read 2180 times)

magentawave

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I have lots of 6 oz and 4 oz E cloth (42” wide) leftover from previous boards that I am wondering if I can use on my next board. For example, instead of using one piece of cloth to glass the entire deck like usual, could I glass it with two of the shorter leftover pieces? Obviously I would overlap the two pieces and could hide the overlap under the deckpad area so it would be less visible. (The board is 8’ x 29 1/4”.)

Would that work ok or would it create a weird hard spot and mess up the flex?
Pluto Platter: 7-10 x 29.25 x 4.25 x 114.5 liters

TallDude

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Use it up. That's fine. The issue you will run into is getting wrinkles when wetting it out where they lap. Have to be careful when you squeegee it. Pinning it down with a finger or second squeegee while you drag the excess epoxy off usually works.   
It's not overhead to me!
8'8" L-41 ST and a whole pile of boards I rarely use.

tarquin

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Try sanding a little trough in the area you will do the overlap. It doesn't take much. Lay the first layer down and wait for it to tack. Make sure you squeegee the excess epoxy out of the trough. Then lay the second layer. With the join in the trough. 
 If you just overlap don't sand it flat after or you will have a weak spot.
 I have used up patches as you said and found the best way was to let the first bit tack before doing the second.

magentawave

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Well, that'll save me from wasting a bunch of cloth and money too. Thanks!
Pluto Platter: 7-10 x 29.25 x 4.25 x 114.5 liters

EastCoastFoiler

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So when you do that overlap, the piece going on top is going to get sanded where it steps down on the edge of the bottom piece, creating a weak line in the middle of the board where most strength is needed.

Also, making boards is hard enough with good materials.  Also the glass is the cheapest part of a very expensive process.  Trying to save money there is unbelievably shortsighted.

Use those piece for foot patches in top of a solid base.

magentawave

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So when you do that overlap, the piece going on top is going to get sanded where it steps down on the edge of the bottom piece, creating a weak line in the middle of the board where most strength is needed.

Also, making boards is hard enough with good materials.  Also the glass is the cheapest part of a very expensive process.  Trying to save money there is unbelievably shortsighted.

Use those piece for foot patches in top of a solid base.

What if I did what Tarquin said?

"Try sanding a little trough in the area you will do the overlap. It doesn't take much. Lay the first layer down and wait for it to tack."
Pluto Platter: 7-10 x 29.25 x 4.25 x 114.5 liters

tarquin

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I did it on a 14 ft SUP to use up cloth and not buy lots more expensive cloth. S-glass and carbon.
 It depends what you are doing.
 Like eastcoastfoiler says if you are just glassing a short board I wouldn't bother.
 You also run the risk of creating a stiff point and the board not flexing evenly. This can actually break a board.
 Unfortunately there is wastage. Maybe find something else to do with the cloth.

 

TallDude

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I've done so many different layups I really don't think you would ever notice. If it was two layers of 5oz CF, then you would notice, but 4oz E-glass? I really doubt it would have any effect on flex or wear it might break. For example, my green machine 9' ripper was just 4 / 6 top and bottom with and extra patch of 6 in the standing area. I kept cutting / chopping the rails with my paddle (bad habit I broke with a narrower paddle). So I added two more rail wraps of 6oz. (this was pre-rail saver era). I eventually had enough more rail chops to warrant another two layers of 6oz along the rails. The flex characteristics didn't change but the board did get a little heavier. If you break a board in half and repair it (stringer-less), you will notice the flex pattern change after the repair. Usually it's not for the better. They usually break near the middle which effects the flex pattern the most. Maybe make two laps with one closer to the nose and one closer to  the tail. That rule generally applies to all structural composite applications beyond fiberglass and carbon fiber.
It's not overhead to me!
8'8" L-41 ST and a whole pile of boards I rarely use.

PonoBill

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Theoretically, it's fine. Boeing uses a lot of composite and they say a 1" lap is the same as continuous material. Nice for them. But e-glass is cheap and I agree with eastCoast--why save on one of the cheapest components? Yeah, it feels wasteful, but you'll find other uses for offcuts.
Foote 10'4X34", SIC 17.5 V1 hollow and an EPS one in Hood River. Foote 9'0" x 31", L41 8'8", 18' Speedboard, etc. etc.

magentawave

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Boat builders overlap their laminates too.

Well, like someone else here said, my concern is that overlapping the cloth will make a hard spot thus potentially making that section vulnerable for breaking and I'm concerned about the flex too. So, I guess I'll stick with using single pieces of cloth like I've always done.

Thanks for all of your input! I really appreciate it. :)

P.S. I started a new thread asking for suggestions on what materials and glassing schedule I should use for my next board.
https://www.standupzone.com/forum/index.php?topic=38106.new#new
Pluto Platter: 7-10 x 29.25 x 4.25 x 114.5 liters

 


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