How long should JB set
- Thread starter JonathanK
- Start date
Bob Kingsbury
New member
J b
I used a lot of JB over the years and find it has pretty well
set at 10-12 hours. This is not a full cure, that happens in more
like 24. High humidity does slow this somewhat. I do keep my
shop temperature about 68-70. and I have no problem with
hardening on time. After mixing and bedding, keep the mix board
handy. You can tell how its doing by testing a thin piece. It should
snap, not bend.
I used a lot of JB over the years and find it has pretty well
set at 10-12 hours. This is not a full cure, that happens in more
like 24. High humidity does slow this somewhat. I do keep my
shop temperature about 68-70. and I have no problem with
hardening on time. After mixing and bedding, keep the mix board
handy. You can tell how its doing by testing a thin piece. It should
snap, not bend.
M
MarkR
Guest
The 3 biggest mistakes that people make when using adhesives are to A. Not follow the directions. B. Not follow the directions and C. To try to rush things up and by not following the directions!
If your parts and room temperature are between 65 and 72 degrees then 24 to 36 hrs later you should have about full cure (means full strength), up to a point a warmer temperature of the parts and the room will quicken the cure time somewhat...I wouldn't want to go beyond about 90 degrees for the parts and whatever room temperature that you can stand.
In other words, you would be much better off to let it cure 24 to 36 hrs.
Oh Yeah! it's not really advisable to use more hardner than is recommended because it accelerates the cure rate and decreases strength.
Mark
If your parts and room temperature are between 65 and 72 degrees then 24 to 36 hrs later you should have about full cure (means full strength), up to a point a warmer temperature of the parts and the room will quicken the cure time somewhat...I wouldn't want to go beyond about 90 degrees for the parts and whatever room temperature that you can stand.
In other words, you would be much better off to let it cure 24 to 36 hrs.
Oh Yeah! it's not really advisable to use more hardner than is recommended because it accelerates the cure rate and decreases strength.
Mark
B
Big Al
Guest
I have to go along with the 24 full cure idea, the question is at shop temperatures. The question is at what is the shop temperature? My shop temperature in Palmer, Alaska might be a little different than say the shop temperature of a shop in Phoenix, Arizona this time of the year. I still use the set aside method of the left over bedding compound for testing a glob before I pull for clean-up, which is before the finale cure time.
M
MarkR
Guest
The higher the initial parts temperature and the temp of your shop, the quicker that epoxy will set. I'll bet that if you contact the manufacturer, they will supply you with a temp/time chart for that specific product.
I would think that 90 degrees would advance the setup 25% but dont take my word on that. I use a plastic mixing cup to weigh both parts unless the directions insist on measuring volumetrically. Much as in weighing powder charges, proper mix ratios will help to insure that your job achieves full advertised strength at the proper time.
Mark
I would think that 90 degrees would advance the setup 25% but dont take my word on that. I use a plastic mixing cup to weigh both parts unless the directions insist on measuring volumetrically. Much as in weighing powder charges, proper mix ratios will help to insure that your job achieves full advertised strength at the proper time.
Mark
Last edited by a moderator:
J
JSchopper
Guest
My rule of thumb has been: Follow the directions, and then give it another 12 hours
M
MarkR
Guest
How long should does JB need to set on a glue-in action before the rifle can be shot? I should have it set in by tonight, and really want to shoot on Sunday (that big box of 108 bergers and kegs of XBR are calling my name!!)
Zane Athey used JB to rebed a rifle that broke loose on Friday. He shot Saturday morning. I don't remember how well he shot, but I seem to remember him taking home some wood.