epoxy formulas????????

BHQ

BHQ

we'll miss you
Silver Member
i ran out (spilled it actually) of the bob smith industries 20 minute finish cure that i normally use for coring and for sealing cues
i ran to a local hobby shop that i knew had it
well, they were out of it, so i got the 30 minute slow cure to hold me over till my prathers order gets here, figuring it'll just take longer to dry
anyways, the first thing i noticed is the 30 minute is much thicker than the 20 minute
i mixed up the 30 minute, wiped onto cue with a plastic spreader as i always do
ONE HOUR later the cue is almost dry, still a little tacky though
when i do this with the 20 minute , it's a good 12 hours minimum to be dry
confused :roll:
 
Why is it called 20-minute epoxy if it dries in 12 hours?:eek::grin:

I don't trust stores' storing habits.
 
Epoxy Timing

Hi,

Two part chemical products do not dry they have a set and a cure chronology. There is a big difference between set time a cure time and the cure time is highly effected by environmental factors. Like concrete products, it is set and you can walk on it or use it for light duty in 24 hours but it does not cure completely for 30 days to it's full psi strength. Concrete for example is much stronger when you keep it from getting too hot and it cures at a constant temperature.

Joey also brings up a good point about the shelf life of this stuff. You want to buy your chemical items from a supplier that is moving the product all the time.

I use G5 5 minute epoxy for my cue sealing and in some humidity conditions it still feels a little too tacky to sand the next day. When in doubt wait another day to sand.

I have found that I get a much better flat sanding process when I wait for it to be cured all the way. Sanding something that feels rubbery is bad in my opinion. I want my surface to be hard feeling so that the sanding medium has a low friction coefficient. I don't want the paper to be dragging the sealer because it is tacky and the will gum it up.

Foremost, temperature is a huge factor when sealing or spraying your cues. Before I had complete temperature control of my sealing and spraying, my results were all over the place. Some days I would think I was getting pretty good at my desired result, then all of a sudden I would have bubbles in the sealing layer or my finish would not buff out the same.

With the products I use, I have found that when I control my environment between 75 and 80 degrees the results will be completely repeatable.

Rick Geschrey
 
Last edited:
scdiveteam said:
Hi,

Two part chemical products do not dry they have a set and a cure chronology. There is a big difference between set time a cure time and the cure time is highly effected by environmental factors. Like concrete products, it is set and you can walk on it or use it for light duty in 24 hours but it does not cure completely for 30 days to it's full psi strength. Concrete for example is much stronger when you keep it from getting too hot and it cures at a constant temperature.

Joey also brings up a good point about the shelf life of this stuff. You want to buy your chemical items from a supplier that is moving the product all the time.

I use G5 5 minute epoxy for my cue sealing and in some humidity conditions it still feels a little too tacky to sand the next day. When in doubt wait another day to sand.

I have found that I get a much better flat sanding process when I wait for it to be cured all the way. Sanding something that feels rubbery is bad in my opinion. I want my surface to be hard feeling so that the sanding medium has a low friction coefficient. I don't want the paper to be dragging the sealer because it is tacky and the will gum it up.

Foremost, temperature is a huge factor when sealing or spraying your cues. Before I had complete temperature control of my sealing and spraying, my results were all over the place. Some days I would think I was getting pretty good at my desired result, then all of a sudden I would have bubbles in the sealing layer or my finish would not buff out the same.

With the products I use, I have found that when I control my environment between 75 and 80 degrees the results will be completely repeatable.

Rick Geschrey
Click to expand...
hi rick
i understand cure & dry
but, wouldnt you think the 30 minute would take longer than the 20?
i had just a dab of the 20 minute left , so i went thru the same procedure on a scrap piece of wood
that was about 2 hours ago and it's still like water wet, where the 30 minute epoxy i did earlier is damn near dry to touch , dry not cured
the store i bought it at goes thru thier epoxies fairly quick, that's why he was out of the usual 20 minute i buy
 
Bad Batch

BHQ,

Sounds like you got some bad stuff. Joey's comment about Stores and storing may be spot on.

Rick
 
I don't want to say you didn't mix properly. I think u k ow what your doing there. Maybe just cheap epoxy. I don't use west system I use just altas 30 min. Alot of makers feel west is much much better.
 
Bad Batch

BHQ,

Sounds like you got some bad stuff. Joey's comment about Stores and storing may be spot on.

Rick
 
dave sutton said:
I don't want to say you didn't mix properly. I think u k ow what your doing there. Maybe just cheap epoxy. I don't use west system I use just altas 30 min. Alot of makers feel west is much much better.
Click to expand...

atlas 30 minute is made by bob smith industries
same stuff prathers sells, but i dont think prathers has thier name on it, package still says BSI
it's the same thing i have,
bsi just labels it for different customers
i guess i'll find out tomorrow when i start sanding
as rick said, if it starts turning into bubble gum,
then i'll know it's a bad batch

just for the helluvit i just glued up a scrap piece of buckhorn joint onto a dowel
tomorrow i'll chuck that up and see if i can break it loose
 
JoeyInCali said:
Why is it called 20-minute epoxy if it dries in 12 hours?:eek::grin:

I don't trust stores' storing habits.
Click to expand...

That is the open work time of the product. Most epoxies will take 5 to 7 days for a full cure. I wouldn't do so much as look at a glued piece for a minimum of 24 hours no matter what flavor of epoxy is being used.


<~~~this, of course, is JMHO.............................
 
Cure Time

Hi,

I tend to agree with Dave about minimum of 24 hours and I use 5 minute G5. I usually wait over 2 days.

I like the 5 minute because I can put a coat on, wait 2 minutes, mix up another batch, put on a second coat, wait two minutes, mix another batch, put on a third coat.

I talked to chemical engineer and he told me as long as I put the multiple coats on within the set time, I will get a monolithic coating of the product using this layering method.

Since I have been putting on three coats, I have not burned through during my flat sanding process. I can sand more aggressively for better leveling without worrying about seeing the color of the wood on my sand paper. Before 3 coats it was hit or miss.

Rick Geschrey
 
It looks like you might have got a bad batch of epoxy.
Normally 20 min and 30 min is the work time ou have before the resin starts to kick or gel or curing.
It is possible that there is a problem with the batch of hardener. You can test this by mixing up some 20 min resin with 30 min hardener.
Usually there is a batch number. You could contact BSI and ask for their comments. They even give you a replacement.
The 20 min resin I have always used takes longer to set as it is a skinning laminating epoxy. With laminating epoxies, they take longer to cure even though they have quite a short potlife or work time. This is beause the resin needs to capillery into the smallest part of the glass or whatever fibre to make the strongest possible bond.
The 30 min epoxy is more like a general epoxy adhesive -glue. So it is quite possible for that to seem cured quicker.
Most epoxies need about 72 hrs for full cure but are usually 90% buy 24 hrs.
Neil
 
Brent, I use the same epoxy, and have bought it from Cue Components, and online modeling stores, and ALL with the same result as you mentioned. On the BSI website it actually states you should heat up finish-cure to about 85 degress before mixing and using, he recommends putting it in a microwave for about 10 seconds, with the caps off as this will also allow for the moisture that may be in them to escape, thereby extending the shelf life. here are the quoted lines from his site:
"For best results, FINISH-CURE™ should be heated to a temperature above 85 degrees F"
"The epoxies can be heated in a microwave oven for about 10 seconds so that they flow easier. The heating process, with the caps off, also releases any moisture that can be absorbed by epoxies. Their shelf life, therefore, is virtually unlimited."
http://www.bsi-inc.com/Pages/hobby/epoxies.html
I have done the microwave deal, but as the bottles get emptier, you MUST reduce the time appropriatly, and also if your microwave is a powerful one, as my new one is, Don't put it in for more than 6 seconds IMO.
I have also used System 3 clearcoat epoxy, from Woodcraft, and it too takes about the same time as Finish-cure. It will take longer if there is a high humidity enviroment, or low temp. I believe Conetip is correct about it needing to seep into the wood pores, fiberglass, etc. so it seems to be designed to be this way. I have never been able to apply additional coats until about 6 hrs. after the previous coat. I have had it actually not harden at all, even days later. (I just got done scraping it off of 2 cues today with that problem) I believe that is due to old stuff, as it usually happens near the bottom of the bottles.
Hope this helps,
Dave
 
BarenbruggeCues said:
That is the open work time of the product. Most epoxies will take 5 to 7 days for a full cure. I wouldn't do so much as look at a glued piece for a minimum of 24 hours no matter what flavor of epoxy is being used.


<~~~this, of course, is JMHO.............................
Click to expand...

You mean my 24-hour epoxy has an open work time of 24 hours?
It has a 30-minute work time but they don't call it 30-minute epoxy.
BSI really needs to relabel their epoxy.
 
Epoxy applicator

This is an interesting thread. Got a question. What is the best application method for epoxy? By hand with rubber glove, plastic applicator, or some other method. I'm never quite happy, and just wondered if there might be a way to improve. Thanks for any help. :smile:
 
Epoxy applicator

This is an interesting thread. Got a question. What is the best application method for epoxy? By hand with rubber glove, plastic applicator, or some other method. I'm never quite happy, and just wondered if there might be a way to improve. Thanks for any help. :smile:
 
Epoxy

One suggestion I will suggest when working with epoxy is to let the epoxy "sweat". After you have mixed your epoxy to your satisfaction let it sweat for
awhile--the time for sweating depends on the epoxy, i.e., 5-minute about 30
seconds, 10 min. about 2 mintes ans so on. After the sweat period re-stir and use. You will have better results if you remember to "sweat" your epoxy.
 
Palmetto cue said:
This is an interesting thread. Got a question. What is the best application method for epoxy? By hand with rubber glove, plastic applicator, or some other method. I'm never quite happy, and just wondered if there might be a way to improve. Thanks for any help. :smile:
Click to expand...
i use a plastic squeegie to smear it on ,
then a playing card to smooth out
recently got some BIG math flash cards, about 3x5 ,
and i get to learn while i'm doing it :eek:
i like the cards, i cup them around the cue and go up & down cue several times
tends to not leave too many ridges
 
Last edited:
I have been using bobby smith for over 12 years and you are right, the working and cure times are different and I agree "backwards" on the 20 and 30 minute. Do a search under Bob Smith Industries it will give you all the info you need. Hope this helps you out...
 
You must log in or register to reply here.
Back
Top