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Epoxy question
I just had a rather unsettling experience with a popular brand of Epoxy setting up way way faster than advertised.
It was a newly purchased (double barrel) two part, 2-ton type with a thirty minute rate of working time.
Room temperature was 70 degrees, and I mixed one-third total ounce (both parts)for 20 seconds. Within ten minutes I was ready to glue. I was shocked to find the mixture already getting hot and turning over.
Does anyone know what went wrong? I am sure of both my mixing time, and lapsed time getting the reel seat cleaned before glueing.
Does this stuff have a shelf life? And, does
this sound like what old epoxy would do.
The amounts mixed (resin & hardener) had to be quite equal, as the double barrel dispenser has a single common syringe plunger.
I have never had this happen before, and didn't know whether or not it is common.
Thanks in advance for any help/advice you
folks with much more experience than I, can
give me.
Sincerely, Panfan
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Panfan; From your description it sounds to me that somehow you got unequal amounts and ended up with more hardner than resin....thus the fast setup time. May I suggest for future rod handles and reel seat assemblies, you purchase some Rod Bond. This is a paste type 2 part epoxy made by U-40 and is the standard epoxy used by most of us custom rod builders. The beauty of Rod Bond is that it is a paste with a rather slow setup time. It allows you to take your time working with it with plenty of time to cleanup excess around handle and reel seat, sets up overnight and is flexible once cured, unlike many of the other 2 part fast drying epoxys. Certainly been a great product in my opinion.
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Gentlemen, Thank you so much!
JC: It never entered my thick skull that the
double openings might not be the same.
David: I will heed your advice on Rod Bond.
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Did you mix up a very large amount of the epoxy? If you did, the mixture could have got too hot and increased the cure rate. Curing epoxy is an exothermic reaction e.g. it generates heat as it cures. a normaly small volume can disipate the heat generated to the outside, but a big glob can not get heat out from the center quick enough and the mixes temperature increases. I like to mix my stuff on a plate of glass with a spatula. It helps insure good mixing and the stuff doesn't warm up.
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A couple of epoxy tricks I picked up during my career as a architectural model builder.
1. Squeeze the epoxy out in two side by side ribbons. Layout the ribbons simultaniously and judge the proportions by the length of the line. Don't trust the marks on the little tubes, a small air bubble inside one of the tubes can throw things way off. Much more accurate than judging the size of two blobs. Doing both parts at the same time means that both ribbons spread out at the same rate. If you do one part first it flattens out and you can't compare it's size to the second part as accurately. By making a linear ribbon you can see small differences more easily. A 25% difference in a 1" long ribbon shows up as a .25", in a round blob it makes a difference of less than .088", since area is a function of the radius squared.
2. Squirt the ribbon into the corner of a plastic sandwich bag. close the bag and squeeze the epoxy into a corner and twist it into a little 'strawberry'. Knead the bag to mix and snip of the corner with a sharp blade for a handy applicator. If you mix on a piece of paper or alum. foil its hard to prevent it from spreading out, you don't know if the part that is spread out is epoxy A or B or a mix of the two, possibly upsetting your proportions. In the plastic bag you can be sure that every drop of both parts gets into the mix.
3. Use an epoxy filler for most applications. The filler increases the surface area of the matrix and increases the overall strength as well as improves the gap filling and flexibility. Same reason we add aggregate to concrete to make it stronger than plain cement. You can purchase commercial fillers such as ground walnut shells or glass 'micro-spheres' from the epoxy suppler or from most model building shops. Do to the increased surface area the epoxy will set faster, so use the slow stuff. Adding 50% filler to 5 min. epoxy will make is set in about 30 seconds.
4. Clean up with regular household vinegar. A little vinegar on a paper towel will wipe off any epoxy that gets in the wrong place or is squeezed out of the joints, and it won't damage cork, varnish or metal fittings.
I have used Devcon 2-Ton epoxy that sat on a shelf for 2 years or more with no appearant problems, heat will ruin it quickly however. Just make sure you store it in a cool place.
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More great advice and shared knowledge...More
humble THANK YOU!
Sincerely, Panfan