t-88 mix ratio tolerance

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skybound

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Mar 24, 2015
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I know its 1:1 by volume and .83:1 by weight. I've got graduated measuring cups and I very carefully pour out the epoxy into them and make sure I'm as close to that as I can get.

But I noticed today, my two bottles that started filled the same have ended up now mismatched by ~3-4% Some of that may be from the few times the hardener doesn't wanna stop coming out the tip and I end up wasting a bit wiping it off with paper towels, but I can only assume that for the most part my mixes have been 100:103 resin:hardener. So, how tolerant is the 1:1 ratio of mismatch? I figured 3% isn't an issue, but what would be?

Also, being a single male there is nobody to yell at me for using my crockpot full of water to warm the epoxy. I get it to 95° and let the epoxy sit in the water until its warmed and it'll flow easier. Is there a limit on how hot those should get? I figured that anything less than the max service temp of 160° would be fine, and I limited it to under 105° so the waters not too hot.
 

TFF

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It is very tolerant, that is why it is a good homebuilders material. Some people's precision is not so much. I would mix as best as you can 1:1 and when you are out of one and have a touch left in the bottle, chunk it. Dont try to make up for mixing mistakes to get all out of it; then you are accepting less quality on the front end instead of the best you can do. You dont want to get it too warm unless you can use it before it gels and you loose your working time. You are just trying to get the crystals to melt in. If you need thinner epoxy, use the System Three Clear Coat; it is thinned T-88.
 

Rockiedog2

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It is very tolerant, that is why it is a good homebuilders material. Some people's precision is not so much. I would mix as best as you can 1:1 and when you are out of one and have a touch left in the bottle, chunk it. Dont try to make up for mixing mistakes to get all out of it; then you are accepting less quality on the front end instead of the best you can do. You dont want to get it too warm unless you can use it before it gels and you loose your working time. You are just trying to get the crystals to melt in. If you need thinner epoxy, use the System Three Clear Coat; it is thinned T-88.
What TFF said. An easy way to measure accurately is mark a small stick with your ruler one mark for each part. then hold the stick against the side of a straight wall cup(viennie sausage can) inside the cup and pour to the mark. i use the same viennie can til the hardened left over glue is about half way up then I get to eat another can of viennies. Looking forward to those viennies will keep you rollin on your project.
 

wiloows5050

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Elk Grove Ca
For larger pours I use the T88 cartridge in a caulking gun. I hold it vertical and get both side even wiping off the excess then squeeze off what I need then put the plug back in. So far it has been right on for me. It actually works better cold.
 

Aerowerx

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Check the System 3 website for their technical documents. They mention the tolerance.

I weigh mine on a homemade scale (see my build log), and have noticed the same thing about one being used faster. Not sure, but my thought is that the density of the resin and hardener are different. I also noticed that they certainly have different viscosities.
 

Davefl42

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Fl
I bought a $20 harbor freight electronic gram scale and mix west system by weight easier to mix small amounts for rib building.
 

amv8vol

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Yes, I forgot about the cartridges, they are terrific for larger and time comsuming glue ups. No mixing, just squeeze and go, premeasured and premixed. Expensive though almost 2X.
 

Abraham Leket

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For the past 2.5 years and consume almost a gallon of T88 (pured on my humble FRED) I join AMV8VOL & Kyle suggestions- 100 Gram precision scale ONLY.
The T88 will take small deviation of part B from time to time- mainly in the summer. In the winter- when you have 40-60F in the workshop- T88 will NOT tolerate excessive part B and you will end up with a brittle joint.
Yes-its a drag to measure each and every single batch- but when they are small-like in the EAA video- you can get away with "eye measure". In a large batch (0.15 OZ and up), aimed at larger jobs-you can screw up practically a whole section of an aircraft- and in 3000 feet your-"widow type mixing" kicks in..
In my opinion EAA should at least post a warning in the video not to emulate the method shown on larger batches- "by eye".
Another issue is workshop temperature- overlooked by novice builder but a major player for the senior one- try to schedule
critical joint construction to the 60F and upward zone. T88 is not a miracle glue-it has limitations and should be treated always with all its components (part B+temp) taken well into consideration.
 
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Beragoobruce

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+1 for the scales. I bought a digital scale on Fleabay from Hong Kong for $10. It's way less messy, & you can measure really small quantities just as accurately as big ones.

And both my A & B bottles ran out exactly the same time!
 

skybound

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Mar 24, 2015
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Columbus, OH
Thanks guys, Amazon has an $8 .01g resolution scale, so I guess I'll pick one up. Mixing in dixie cups vs plastic medicine cups will probably net savings more than the cost of the scale anyways.
 

amv8vol

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Mixing in upside down soda cans a la the EAA video will save even more. I did my entire project (so far) with soda cans and T-88 U-tah cartridges
 
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