Strain Gauge adhesives subsitute?

[M.Haroon Azhar]

Hi.
I am a student of Mech Engineering
i want information from you about starin guages bonding. we are designing an apparatus for combined loading and we need strain gauges for that purpose we have already purchased the strain gauges and now we are searching for its bonding kit and after a long search we are unable to find something less expensive . I would be very thankful if you help us.Please give us an idea that we can implicate for bonding of strain gauges other than bonding kit , becz it will cost us too much if we ordered it online
also you can tell us if there is a way of buying less expensive kit

 

[strantor]

Bonding what to what?

 

[M.Haroon Azhar]

bonding strain gauges to steel/Aluminum L-shaped rectangular bar

 

[alec_t]

Have you consulted guidance such as this? What temperature range? What type of adhesive?

 

[M.Haroon Azhar]

yes temp rane between 10 to 35 and adhesive is z-70 used for experimental purpose but hbm is quite expensive and they dont deliever in pakistan
any alternative?

 

[MikeMl]

yes temp rane between 10 to 35 and adhesive is z-70 used for experimental purpose but hbm is quite expensive and they dont deliever in pakistan
any alternative?

Not really. The bond between the Al and the gauge must transmit the strain without deformation. Regular epoxies are "gummy" (compress-able), so they totally screw up the strain readings... The adhesive, when cured, literally must be "as hard as a rock"...

 

[alec_t]

z-70 is a cyanoacrylate adhesive, so won't any cheap cyanoacrylate adhesive (aka 'superglue') do the job?

 

[kinarfi]

alpha cyanoacrylate, super glue, worked for me, I used it on a steering shaft to detect the torque applied to the steering as back feed to a power steering unit.

 

[MikeMl]

There are hundreds of different cyanoacrylate formulations. Kinfari's solution may have worked because all he needs is a "relative" stain indication. If his adhesive "loses" some of the strain, it doesn't matter, because all he has to do is turn up the feedback gain...

To measure absolute (not relative) strain, you have to use the proper adhesive...

 

[M.Haroon Azhar]

Thats what i am asking, i cant buy these adhesive kits ,its quite expensive and as a student i cant afford these so i am looking for an alternative which can help me and give same strength so that i would be able to get good results
help me out

 

[MikeMl]

Since you are a student, you must understand the scientific method: Your postulate: Cheap Cyanoacrylate is as good as "Stain Gauge Bonding Adhesive" which is marketed for the purpose. Prove it by doing some comparitive studies..., or find someone who has...

 

[JonSea]

Superglue works well over the short term...days, weeks, months even. For long term use, the proper adhesive will ensure the best results.

 

[schmitt trigger]

I've used common cyanoacrylate adhesive with good results.

In my experience, the surface preparation is as important as the adhesive itself. It must be smooth, and absolutely clean from any sort of surface contamination.

 

[Reloadron]

I have to agree with Mike. Super glue may work but is not quite a solution to doing bonding. In additin to just the bonding there is the surface prep, followed by cleaning with a mild acetic solution followed by a neutralizing solution and then the bonding agent based on temperature. Even when the strain gauge is placed there is a required force. I used everything from Measurements Group Inc. which is now a part of Vishay. You may want to give this a read. That is an Omega Engineering version but note what is involved. I can tell you that unless done correctly any data you get will be garbage. While common cyanoacrylate adhesive (super glue) will work in most cases it is far from an ideal solution. Even different types of super glue fail at different temperatures. Anyway, you can try super glue with a good prepped surface and see what you get but when planning the use of a strain gauge the cost should have been figured in. Here is another good read on doing the prep.

Ron

 

[Reloadron]

alpha cyanoacrylate, super glue, worked for me, I used it on a steering shaft to detect the torque applied to the steering as back feed to a power steering unit.

How did that work out for you? I remember when you were doing that project.

Ron

 

[gary350]

Read the book, Adhesive Technology. **broken link removed**

Adhesives have ratings from soft to hard to flexible to ridge. I glued aluminum scope mountains to my rifle with ridge glue it fell off after 3 shots. Next I tried semi ridged adhesive the scope mounts are still there after about 400 shots on my 300 Winchester mag rifle. Ridge glue is less shock resistant than semi ridged. Ridge adhesive is strong but like glass it breaks if you hit it with a hammer but hit a piece of rubber with a hammer it bounces off and returns to its original shape. Read about different types of adhesive you will learn what will work best for your application but you still need to do testing to make sure it works.

 

[Reloadron]

Read the book, Adhesive Technology. **broken link removed**

Adhesives have ratings from soft to hard to flexible to ridge. I glued aluminum scope mountains to my rifle with ridge glue it fell off after 3 shots. Next I tried semi ridged adhesive the scope mounts are still there after about 400 shots on my 300 Winchester mag rifle. Ridge glue is less shock resistant than semi ridged. Ridge adhesive is strong but like glass it breaks if you hit it with a hammer but hit a piece of rubber with a hammer it bounces off and returns to its original shape. Read about different types of adhesive you will learn what will work best for your application but you still need to do testing to make sure it works.

I use loctite threadlocker Blue 242 and only on the mounts themselves. The rings I don't apply anything other than torque on the ring screws. That includes a pretty wide range of calibers. My enjoyment of 300 Win Mag and 7mm Rem Mag are pretty much done and calibers of days past. Anymore the 30-06 is about my pain threshold. As I get older the ouch becomes more pronounced. On the bright side 22 LR is still fun to shoot.

Ron

 

[gary350]

I use loctite threadlocker Blue 242 and only on the mounts themselves. The rings I don't apply anything other than torque on the ring screws. That includes a pretty wide range of calibers. My enjoyment of 300 Win Mag and 7mm Rem Mag are pretty much done and calibers of days past. Anymore the 30-06 is about my pain threshold. As I get older the ouch becomes more pronounced. On the bright side 22 LR is still fun to shoot.

Ron

Factory loads burn all the powder in 50% of the barrel length this gives your shoulder and very hard punch. I reloaded so all the powder burned in 95% of the barrel a slow burn powder gives your shoulder a push not a punch. The added powder burn length increased the bullet velocity and with no hard punch shots were more accurate. I use to shoot soft drink bottles full of water a 1/4 mile away are rarely missed 1 out of 100 with a 4 power scope and 165 gr bullets. I don't think I can do that anymore my eyes are not good enough. I have the same scope on my Chinese pellet rifle I can hit a dime at 100 feet. Pellets drop very fast after 125 feet. I had my 300 zeroed in at 200 yard it was 1" low at 100 yards and 300 yards and 2.5" low at 400 and about 5" low at 500 yards. I could shoot anything I could see fairly easy. Now days it is hard to find a place to get a 400 yard shot, rifle ranges only go to 200 yards and that is so easy with a 300 win it is no fun. I lost interest with guns about 1985 only thing I own now is a pellet rifle. I use to have fun shooting Red Tracers with the 300 at a distance of 1 mile.

 

[Reloadron]

Factory loads burn all the powder in 50% of the barrel length this gives your shoulder and very hard punch. I reloaded so all the powder burned in 95% of the barrel a slow burn powder gives your shoulder a push not a punch. The added length increased the bullet velocity and with no hard punch shots were more accurate. I use to shot soft drink bottles full of water a 1/4 mile away are rarely missed with a 4 power scope and 165 gr bullets. I don't think I can do that anymore my eyes are not good enough. I have the same scope on my Chinese pellet rifle I can hit a dime at 100 feet. Pellets drop very fast after 125 feet. I had my 300 zeroed in at 200 years it show 1" low at 100 and 200 and 2.5 low at 400 and about 5" low at 500 yards. I could shoot anything I could see.

My brother is a 300 Win Mag shooter, he is also 10 years my junior . I just finished loading some .308 Winchester for a chronograph experiment. I started hand loading in '72 when I came home from Vietnam, I just had this thing about making my own accurate ammunition. Yeah, getting old sort of sucks I turned 66 in February but I love being retired with more range time. What sucks is NE Ohio in the winter. With age I have become a fair weather shooter. The winters lead to more indoor range handgun time. My longest rifle is 500 meter line. Fortunately my vision is still pretty good. The problem being finding a range that extends beyond 500 yards around here. My outdoor range is just under an hour drive.

I have a plan for this summer using a strain gauge. I want to capture some .308 Win using my .308 bolt gun. Not interested in actual chamber pressure as much as looking at the pressure curve. Something along these lines is what I have in mind. I find with age the lighter recoil calibers have become my new best friend. Till now I thought I was the only shooter in the forum.

Ron

 

[kinarfi]

alpha cyanoacrylate, super glue, worked for me, I used it on a steering shaft to detect the torque applied to the steering as back feed to a power steering unit.

How did that work out for you? I remember when you were doing that project.
Ron

Ron
It worked out well, the strain gauge did fine, but the amplification circuit or something in the system was radio frequency sensitive, if a walky talky was keyed any where near the car, parked or while driving, it caused a hard right turn, I passed a High Way Patrolman who was about to use his radio so I prepared for my steering to turn right and sure enough, it tried, and he was some 100 feet away I eventually went to a commercial steering unit, but I had fun designing and building this one and was proud that it worked, in spite of this flaw. It's my thinking that the stain gauge itself was the RF receiver and I was using a INA122 intrument amplifier set for a gain of 1000.
Jeff