How do you measure out your glues? For stuff like smooth-on that calls out a 1-1 by volume, but that stuff is so thick, its hard. I normally try to measure by weight, but usually the resin and hardener aren't the same to begin with. Just not sure if there is an easy way or not.
I use a teaspoon and get it close as I can. My personal opinion is it doesnt have to be labratory close to work jsut fine. URAC is 2-1 and I use my teasppon measure with success.
You can also get a cheap digital scale from harbor frieght. I use a scale for my measurements.
I have built over 10 bows with smooth on.. and have always eye balled it... never had a separation problem yet.
I use scrap wood to scoop out and make a clump of each and just make sure both clumps look about equal..
I also look for the overall color when mixed.. should be a milky yellow for smooth on.. if it is to white, add more yellow... too yellow.. add more white.
Again, never had a problem.
For Smooth-on we are often told it is best at a 50/50, but on the can it says to improve bonding characteristics you can add more of the white stuff than the yellow...as much as 2 to 1. So, when I mix it up, I shoot for the 50/50 but if I have doubt I will add a bit more of the white just to make sure I don't go on the low side with the white stuff. I probably end up with about 55/45 or something like that. When my cans are almost empty, I will have a little of the yellow left over, but not much at all. If memmory serves me correctly, that is part A...but double check please. It's been a while since I read the can.
I use 3 fluid oz plastic cups, the ones used in bathrooms.. filled to the top..I have been using large wooden popsicle sticks to put glue in cups. I use 1 and 1/2 cups of each part but mix two 3oz cups of each part.. yes I waste plenty of glue but so far no problems
I go down to the pharmacy and get some oral dosing syringes.
Use one syringe for each part of the epoxy. You can draw the fluid right out of the can and measure it precisely.
Very clean and accurate. Sometimes I clean them, sometimes just throw them away. The pharmacy just gives them to me.
CJ
If you measure by weight the ratio is 100:83 resin to hardener. it takes about 1800 grains for one bow if you spread it real thin with a putty knife.
QuoteOriginally posted by PEARL DRUMS:
I use a teaspoon and get it close as I can. My personal opinion is it doesnt have to be labratory close to work jsut fine. URAC is 2-1 and I use my teasppon measure with success.
PD,urac is 13 to 100. not 2 to 1. thats 13 powder to 100 liquid. i use a digital scale set to grains. for example if i am glueing on just handle laminates. i will measure out about 21 grains powder to 150 grains liquid. this will be enough to do the job with little or no waste.don
My can's must be mis-marked, or Im getting real lucky that anything has stuck over the years? The instructions I have say one part hardener to two parts resin? Who knows....
You guys a are comparing two different measurements, one is using weight and the other is using volume.
You may be right Walt. Volume is what I use with my teaspoon science!
2:1 ratio is still 2:1 whether you use volume or weight, as long as you stick with the same standard when mixing. Unless the instructions specified to use a certain unit of measure then that part is up to the user depending on how much you need to mix up. 2 teaspoons of this, plus 1 teaspoon of that. Or 2 ounces of this, plus 1 ounce of that.....it's still 2:1 ratio.
I've used plastic throw away cups with graduations on the side so I can tell how much I'm mixing, but I used to get those free from work so getting the cups wasn't a problem then. I imagine you could buy them at anywhere that sells painting supplies? I'd try just a dab first to make sure it wouldn't eat through the plastic though before I mixed up a whole batch.
QuoteOriginally posted by Walt Francis:
You guys a are comparing two different measurements, one is using weight and the other is using volume.
your right walt. the urac can says both. 13 to 1 by weight and 1 to 2 by volume. sorry PD. my bad.don
I was just about ready to drive to Buffalo Don......................but the roads suck!
they suck here too. snow covered at the moment.don
QuoteOriginally posted by SEMO_HUNTER:
2:1 ratio is still 2:1 whether you use volume or weight,.. 2 teaspoons of this, plus 1 teaspoon of that. Or 2 ounces of this, plus 1 ounce of that.....it's still 2:1 ratio.
No. Just no. If 'this' is a different density than 'that' then volume ratio and weight ratio are very different!
With URAC one part is dry and the other wet. You will have very different weight or volume ratios!
One teaspoon of 'this' may weigh twice as much as one teaspoon of 'that'. In such a case the volume ratio would be 1:1 and the weight ratio 2:1 for the same exact materials.
Consider mixing lead shavings with aluminum shavings for example.
CJ
I have one comment to add as far as appearence.
When properly weighed out and mixed it will be milky white, if it still is yellowish or streaky it is not mixed enough. I weigh my parts A/B exact and Ive mixed by hand moderately and with a mixer blade on a drill and I see a difference. I can get the same good mix by hand you just got to mix it alot more so dont scrimp here.
2:1 ratios are all the same, after all ratio is ratio. But volume and weight ratio's do not translate equally. I was going to argue with you Chris, but I seen your profile pic and you got me by about an 1" and about 25#'s! Daddy didnt raise no dummy!
Wait. Perl, are you saying I'm in trouble here?
C'mon guys, I was just tryin' to help. :help:
[looks around nervously] :rolleyes:
CJ
You should be good, Co is quite a ways from Mo........plus I dont think he seen it yet...cross your fingers CJ!
QuoteOriginally posted by CaptainJ:
QuoteOriginally posted by SEMO_HUNTER:
2:1 ratio is still 2:1 whether you use volume or weight,.. 2 teaspoons of this, plus 1 teaspoon of that. Or 2 ounces of this, plus 1 ounce of that.....it's still 2:1 ratio.
No. Just no. If 'this' is a different density than 'that' then volume ratio and weight ratio are very different!
With URAC one part is dry and the other wet. You will have very different weight or volume ratios!
One teaspoon of 'this' may weigh twice as much as one teaspoon of 'that'. In such a case the volume ratio would be 1:1 and the weight ratio 2:1 for the same exact materials.
Consider mixing lead shavings with aluminum shavings for example.
CJ [/b]
Yes they will weigh more and a teaspoon will be more or less than an ounce, that's not what I'm saying!!
A 2 to 1 Ratio is STILL a 2 TO 1 Ratio NO Matter What system of Measure you USE!! Go back and read what I wrote before you try to correct me CJ.
Semo doesn't skeer me Pearl.. I think I could out run em:) Prolly out fish him too...
I measure my Urac 13 to 100...
Im sure you could out fish him Roybert, heck his little nephews can!
I mix it with bamboo laths that are about 10 inches long. One about a half in wide and the other 3/8 or so. I take a glob of white with the big one and a glob of amber with the little one. generally aobut 2 1/2 globs of each. Mix for three minutes. Mixing time is crucial. Check color a good off white is the ticket. I usually have a bout a third of a can of the yellow left. The ticket is to err on the side of more resin than hardner. My limbs always cook the same amount of time and I have never ever had a delamination. It must work so why change it. LOL
Globs and color , that is the word.
God bless you all , Steve
QuoteOriginally posted by SEMO_HUNTER:
Go back and read what I wrote before you try to correct me CJ. [/QB]
Sorry. I read what you wrote in the context of the previous few posts in which there was some confusion about volume vs weight.
Of course you're right that a 2:1 ratio is just that, but I'm right that the ratio doesn't keep when going from weight to volume. Not that you were saying that or anything.
He saw it now PD! But all I have to do is out run you right?
CJ
I've never used Smooth on, so I don't know how thick it is. As such, this idea might not work: Has anyone considered using a simple hand pump like a soap dispenser? You could have two dispensers that put out the same amount per pump. One pump of this, two pumps of that, or whatever ratio you need.
I've worked with a few different epoxy resin systems for laminating fiberglass (aircraft, not bows). Some have one pump for resin, one for hardener. Some have them both in one unit, so when you pull the lever, the right amount of each is dispensed.
http://www.westsystem.com/ss/pumps-and-metering-equipment
You all very well could out run me, I have no doubts about that.
I was always too big to run so I had to stay put and either take an arse whoopin' or deal one out. :wavey:
Geeze, I don't know about Pearly Boy, but I'm just ah shaken in my BVD'S right now:) Looks like skid marks in em from some ole chevy getten out the way of a real truck like a Ford..
But I gotta ask ya Semo, what's ya doing with a fish picture on a Trad Bow site? And LMAO, don't they have any real fish out there? :)
(http://i47.photobucket.com/albums/f165/ROY-CHRIS/texas_arronshouse093.jpg)
Roy, that was the only pic I could find that I was smiling in. :D
I also heard through the grapevine that your wife does most of the fish catching in your boat.
I dunno, just what I heard? :rolleyes: :saywhat:
I must apologize to the original poster for straying this off topic as far as it has, but I think the question was answered a long time ago? Hopefully Roy and I will be forgiven.
LMAO Semo. This has been a very educational and fun thread.
Well, whether or not you learn anything at least we can give you a laugh!
CJ
I agree Matt, we got the best of both education and a laugh from the biggest and OLDEST people on here! I guess I may be a little guilty.......I kinda started it and ran in the other direction like the sissy pants 3 under shooter I am!
LOL! You sissy pants!
QuoteOriginally posted by PEARL DRUMS:
I agree Matt, we got the best of both education and a laugh from the biggest and OLDEST people on here! I guess I may be a little guilty.......I kinda started it and ran in the other direction like the sissy pants 3 under shooter I am!
I would describe is as running like a turpentined cat, or a scalded dog. Hit and run sissy pants. :thumbsup:
So are we having fun yet?
I'm talking smooth on here Semo.... if you use a 100:83 ratio by "volume" and a 100:83 ratio by weight, you are going to have 17% too much hardener on the volume mix.
1:1 volume ratio equals 100:83 by weight with smooth on. and too much hardener will make this stuff brittle.
The advantage to weighing smooth on vs measuring it, is the very thick nature of the stuff makes it difficult to measure volume accurately.
ratio is NOT equal to ratio when you are talking two different forms of measurement. Period
We solved that several posts back. Actually Chris' original post stated that. It was misread and lead to a funny discussion. Period
OOOOOPS!
Read back a bit Kirk. Its some funny stuff! Be sure to have a spare pair with ya, you might pee em'laughing too hard!
2:1 ratio is always going to be just that.
Substitute "Parts" for any unit of measure your heart desires and it will always work as long as you use the recommended ratio. Unless of course the manufacturer specifies to use "Volume" or "Weight" as your unit of measure.
That's the only point I was trying to make, not suggesting that anybody use one or the other.
Make sense?
Matt
I have used smooth on for the 4 laminated bows that I have built so far.
After building the very first one, I learned from others that, what works well is to take both parts, A, And B. And put them in a microwave oven for a short time before mixing. Or put A and B in your pre-heated hot box for 15 minutes or more before mixing. It makes it a lot easier. Good luck John
REALLY???? you put the hardener in the micro wave too? :scared: :scared: :scared:
i put the resin in there for about 15 seconds and mix it into the hardener with no problems, but i never had enough guts to try that.
I was laminating riser blocks, and i got the resin to hot one time before i mixed in the hardener. After spreading glue for about 10 minutes i notice the cup was getting warm.... then it startyed getting HOT!...Damn Hot!. next thing i know the paper cup is actually smoking! :eek:
you guys ever have that one happen? i had mixed a large quantity that exceeded the grain scale max, and i think i may have got too much hardener in there besides heating it to9 much. :o
Nope Kirk, Never ever. I keep a heat gun on my bench and after I mix the epoxy a bit i warm it with the heat gun . stir, warm it some more ect until it is fairly loose. the I warm the lams immediately before I glue up. Not to warm them but to eliminate all the moisture I can. I don't believe warming does anything with lams except that because by the time you start gluing them they are cold again.
God bless, Steve
The first time I used smooth-on, the shop was cold and the stuff was cold. I could barely scoop any out of the jars. I will have to try warming some up next time.
Obviously, cold epoxy (below 70 degrees) is next to useless as it is way too thick and pasty to use appropriately, but...
I personally would NOT warm/heat up the epoxy AFTER I mixed it. I would warm it to 85-95 degrees prior to mixing it by putting it in an open heat box, but I personally wouldn't want it to get over 100 degrees even prior to mixing it. Once it is mixed, I certainly don't want to heat it up (nor do I want it cold). Heat makes it cure and begin to set up. The hoter it is, the less working time you have. It states you have a 2 hour working time at room temp (typically around 75-78 degrees) in a shop, but I suspect that at 100 degrees it would probably BEGIN setting up in about an hour to some mild degree. I don't want it to set up at all until AFTER I put pressure on it in the form...as I want a mildly warm (just warm enough to mix and spread easily) epoxy that when I put pressure on it will actually get driven into the tiniest pores and textured surfaces in the riser and limbs. If it begins to set up when you do your first glass layer...by the time your done with the last glass layer (which if your spreading it well can take up to 45 minutes on some multi-lam bows)...I want to know that stuff will still flow and hasn't set up at all...as I have to get the press assembled and pressurized...and by the time I mixed the epoxy to the time I put the pressure on it...close to an hour has passed. This is why I want my epoxy no cooler than 75-80 degrees, but not much warmer than 90 degrees.
To date, I have never had even a cloudy spot in a limb. I probably shouldn't have said that though...because I will end up jinxing myself on the next one. LOL.
Lee, And I thought I was slow bro. :knothead:
God bless you all, Steve