Wrapping plywood with fiberglass

[ondarvr]

Re: Wrapping plywood with fiberglass

Did you put a nice round radius on all the edges, a 1/2 router bit works well, the edge of plywood is more difficult to do. Glass is made if straight fibers, they don't like to bend around a tight radius.

On flat surfaces it can be technique, heat, amount of resin, type of glass, small splinters of wood, dirt, or other things.

 

[flamron]

Re: Wrapping plywood with fiberglass

Perfect!!!

Did you ever PM me your SHIPPING Address??

Thought I did - I'll send again here in a bit

Did you put a nice round radius on all the edges, a 1/2 router bit works well, the edge of plywood is more difficult to do. Glass is made if straight fibers, they don't like to bend around a tight radius.

On flat surfaces it can be technique, heat, amount of resin, type of glass, small splinters of wood, dirt, or other things.

I don't have a router - I'll see if I can borrow one, though, to round the edges if that helps. Thanks!

 

[flamron]

Re: Wrapping plywood with fiberglass

Perfect!!!

Did you ever PM me your SHIPPING Address??

Your box is full. I probably didn't see that the first time I sent it.

 

[Woodonglass]

Re: Wrapping plywood with fiberglass

OK, well I cleared it now, so if you still need the stuff send me your adress and I'll send it

 

[Yacht Dr.]

Re: Wrapping plywood with fiberglass

YD, Would you please elaborate on the proper preparation? I was under the impression that laminating the edges with fiberglass is what seals them! What did you mean by .. "I can Guarantee you did NOT seal those ply edges prior to your lams"? What type of sealing would you do before fiberglassing?

I did precoat all the sides - but I did this the day before glassing the pieces. Perhaps another precoat right before application is in order? I sanded the wood with 80 grit before precoating as well, and then blew/wiped them clean (air and acetone) and let the acetone "burn" off before continuing.

No voids were in the wood. Possibly because this is MG plywood? (but I'm betting some voids are possible, and I'll fill those if needed if I come across any).

YD - that video would be a great asset for sure! Anything I could see would be fabulous! I seem to do well with emulating stuff when I see it, so that would be an invaluable piece for any newbie I'm sure.

Thanks again to all: YD, ondarvr, woodonglass, and everyone else. Like I said - I'm a total rookie on this stuff. I spent days of searching on here and the internet, and didn't really come across anything that fit my questions. It seems like glassing is almost an artform - probably why I stink at it!

If your going to Glass on edges of ply you have to Make Sure they are Totally Sealed !!

That is what prep is with wood .. Total Seal or the Glass/Wood bond will fail on your initial layup bond.

It will not matter how saturated your glassing schedule will be..it will fail on the initial bond layer .. ( the most important one ).

Like I said..you need Whatever substrate to be completely Sealed. Putting your last coat with 1.5 oz mat can help your seal..but not in every case..

Trust me on this one...

YD.

 

[Woodonglass]

Re: Wrapping plywood with fiberglass

I just went back and read my post in your "What did my wife get me into" thread. I thought that we had discussed precoating the wood and paying close attention to edges. I appears you did that. I really think your problem might be you did not coat the wood again before laying the glass as we discusse previously and then you applied too much resin and glass . Try what was I recommened today with your test piece and see if that doesn't come out a whole lot better. I'll bet it does. Do it in the coolest part of the day or nite. Yeah right, like There is one right now!!!!!! Check your PM

 

[flamron]

Re: Wrapping plywood with fiberglass

I couldn't get a router, so I sanded the edges by hand to knock off the sharp edges.

I have the piece sanded completely and cleaned. (this is the large piece)

I'm going to with woodonglasss suggestion and try out a small little scrap piece to get a good feel on how to do it the way I should have done it. But, it'll need to "cool" down a little first. I'm at a disadvantage because I can't work fiberglass in the back yard due to my 3 year old son. So I have to do it in the driveway, which faces the west conveniently. Just makes hot that much hotter!

Maybe by the time the Mavs game is over tonight I can go out and try my hand at some glassing.

 

[flamron]

Re: Wrapping plywood with fiberglass

Still no good. I'm wondering if my MEKP is bad. I ordered it around the first of March. I've read where it is only good for three months or so. I have a couple more bottles of it, so I'll try those as well and see what happens.

I may increase the amount of catalyst as well to see if I can get it to kick a little quicker. I'm adding the spec'ed amount on the sheet from US Composites. I worked the top part for about fifteen minutes and then waited another thirty before trying to get the edges to lay down. I gave up after ten minutes and came back about thirty minutes later again. It was hardening, but it still wasn't sticky enough. I may have over-saturated the edges again, too.

Pics tonight when I get home.

 

[Cadwelder]

Re: Wrapping plywood with fiberglass

Still no good. I'm wondering if my MEKP is bad. I ordered it around the first of March. I've read where it is only good for three months or so. I have a couple more bottles of it, so I'll try those as well and see what happens.

I may increase the amount of catalyst as well to see if I can get it to kick a little quicker. I'm adding the spec'ed amount on the sheet from US Composites. I worked the top part for about fifteen minutes and then waited another thirty before trying to get the edges to lay down. I gave up after ten minutes and came back about thirty minutes later again. It was hardening, but it still wasn't sticky enough. I may have over-saturated the edges again, too.

Pics tonight when I get home.

Let me do the math right...15 + 30 + 10 + 30. That's an hour and 15 minutes....your resin should have been way past working it by then....I'm guessing not enough MEKP.

Also rounding the edges just a little by hand really isn't enough. The wood needs a good radius for the fabric to "roll over" it good. Also the pretreatment of the wood, as Yach Dr. stated in very important. A glass roller will help too, if you have one.

 

[flamron]

Re: Wrapping plywood with fiberglass

I made up 16oz of resin, which according to the sheet from US Composites means I need to add 1/8oz MEKP (I think - I'm not positive).

 

[Woodonglass]

Re: Wrapping plywood with fiberglass

16oz is 2cups (1/2 Quart) of resin and should require about 1/2oz of catalyst. How big of a piece of wood were you doing? If the wood was already Pre-Coated with resin and dry then 16oz of resin should coat about 2-3 sq ft of wood including the edges.

 

[flamron]

Re: Wrapping plywood with fiberglass

22x57 is the size of the piece

 

[Woodonglass]

Re: Wrapping plywood with fiberglass

Ok well then that was not TO much resin. I am REALLY startin to think the MEKP is bad. Your working time is WAY OFF! It should be HARD as a ROCK in 30 minutes. Especially with Yesterdays Heat. What USC Resin are you using???

 

[flamron]

Re: Wrapping plywood with fiberglass

434 I believe.

I made up another ounce to touch up as well, but that was it. So 17 ounces to lay down another precoat, and then lay down the piece and go over it with the squeegee and brush.

 

[ondarvr]

Re: Wrapping plywood with fiberglass

Avoid using a squeegee on mat, it makes a mess. Use a brush and roller.

 

[Yacht Dr.]

Re: Wrapping plywood with fiberglass

I made up 16oz of resin, which according to the sheet from US Composites means I need to add 1/8oz MEKP (I think - I'm not positive).

Your typical rate at 1.5 % cat is 40cc/gal for non-lowVOC resin .. or 10cc/qt .. or 5cc/pt ..
16 oz is .5 Qt .. or cat rate is 5cc ( based on 40 cc/ oz ) is Correct for 1.5% cat ratio..

You did it right..

16oz is 2cups (1/2 Quart) of resin and should require about 1/2oz of catalyst. .

That would be 20CC or equivalent to catting 2 Qts or resin.. .. Not right for catting 1 pt of resin ..

Ok well then that was not TO much resin. I am REALLY startin to think the MEKP is bad. Your working time is WAY OFF! It should be HARD as a ROCK in 30 minutes. Especially with Yesterdays Heat. What USC Resin are you using???

Ok..

Avoid using a squeegee on mat, it makes a mess. Use a brush and roller.

But using mat and a roller is the way of the trade ..

YD.

 

[Woodonglass]

Re: Wrapping plywood with fiberglass

Flamron,

For your future reference this comes directly from the USC PDF on Mixing ratio's I got my quarts and gallons mixed up and YD was correct as were you on your ratio.

POLYESTER RESIN IS CATALYZED WITH MEKP (METHYL ETHYL KETONE PEROXIDE). THE RATIO IS APPROXIMATELY ONE
OUNCE OF HARDENER PER GALLON OF RESIN. USE THE FOLLOWING RATIOS FOR SMALLER AMOUNTS.
AMOUNT OF RESIN OR GELCOAT HARDENER AMOUNT
1 OUNCE 10 DROPS
1 PINT (16OZ) 1/8 OUNCE
1 QUART (32OZ) 1/4 OUNCE
1/2 GALLON (64OZ) 1/2 OUNCE
1 GALLON 1 OUNCE
THESE AMOUNTS ARE EASILY MEASURED IN THE OUNCE CUP WHICH IS SUPPLIED WITH THE RESIN. THE ABOVE RATIOS
SHOULD GIVE YOU A POT LIFE OF ABOUT 15 TO 20 MINUTES AT 80 DEGREES F. IF YOU ARE SATURATING FIBERGLASS
REINFORCEMENT IT SHOULD BE READY TO RECOAT IN ABOUT 1-1/2 HOURS. TIME WILL VARY FROM WINTER TO SUMMER
SINCE HIGHERS TEMPERATURE PRODUCT FASTER CURING. THE RATIO OF HARDENER TO RESIN CAN BE INCREASED OR
DECREASED BY 50% TO ADJUST FOR WEATHER, THICKNESS OR YOUR WORKING PREFERENCE. TEMPERATURES ABOVE
90 DEGREES WILL DEFINITELY REQUIRE A 50% REDUCTION IN HARDENER AMOUNT.
PLEASE NOTE CAUTIONS ON BOTH THE HARDENER AND THE POLYESTER RESIN. MEKP IS A NASTY CHEMICAL AND YOU SHOULD AVOID
GETTING IT ON YOU. POLYESTER RESIN IS FLAMMABLE. SMOKING OR WORKING CLOSE TO A RUNNING ELECTRICAL DEVICE OR AN OPEN​

FLAME SHOULD BE AVOIDED. GLOVES, FACE AND RESIPIRATORY PROTECTION SHOULD ALWAYS BE WORN.

 

[ondarvr]

Re: Wrapping plywood with fiberglass

Those are not the correct figures for 1.5%

Here is a chart, two actually.

http://www.ccponline.com/tds.asp?id=283



CATALYST CHART

RESIN


VOLUME ?% 1% 1.5%
8 oz. 2 cc 3 cc 4 cc
1 pint 4 cc 5 cc 7 cc
1 quart 7 cc 10 cc 14 cc
#10 can 23 cc 30 cc 45 cc
1 gallon 28 cc 37 cc 56 cc
5 gallon 140 cc 185 cc 280 cc



Gelcoats

VOLUME 1.25% 2% 1.75% 2%
8 oz. 4 cc 4 cc 5 cc 6 cc
1 pint 7 cc 8 cc 10 cc 11 cc
1 quart 14 cc 16 cc 19 cc 22 cc
#10 can 43 cc 52 cc 61 cc 66 cc
1 gallon 53 cc 63 cc 75 cc 86 cc
5 gallon 263 cc 315 cc 373 cc 426 cc



Please excuse the spacing on the amount to add, it won't allow me to make the changes needed, I can edit it to look right, but when posted it doesn't line up correctly.

 

[flamron]

Re: Wrapping plywood with fiberglass

Thanks ondarvr - I actually doubled my catalyst tonight, which put me at 1/4oz for 16oz of resin.

I think I need to triple this stuff to get where I need to be (due to age?).

I did the other side of the board after sanding and cleaning with acetone. It seemed to take a lot better. The edges laid down a lot easier, but I still had like 45-60 minutes worth of work time. I spent that time (after waiting for 10 minutes) getting the edges to lay down and just kept going around the board until they all flattened out for the most part.

If it does bubble up, I'm thinking that when I PB the board onto the flanges, I'll make sure to cover that part up. I'll sand them down first of course.

 

[flamron]

Re: Wrapping plywood with fiberglass

Getting better I think: