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Rank: New User
Groups: Member
Joined: 1/15/2008
Posts: 2
Points: 6
Location: Saskatoon, Canada
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Does anyone else on this forum use Stresscoat? The company appears to have disappeared and I am wondering if there is a replacement out there?
Stresscoat is (or maybe was) a brittle paint that would crack when a load was applied to the part. The cracks would form perpendicular to the direction of strain in high stress areas. This allowed you to orient strain gauges in complicated, high stress locations without FEA support or when FEA was uncertain of the vector. Complicated shapes like castings and large weldments were not an issue since it was sprayed on. The biggest issue was the temperature sensitivity; too warm and it wouldn’t crack, too cold and it cracked everywhere.
It was great for life calculations because you could use actual data for the ugliest locations. Sometimes we did not even use FEA, just Stresscoat for the vector and high locations.
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Rank: New User
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Joined: 7/1/2008
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Location: Pella, IA
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Our company utilizes stress coat on the majority of our machines. Our safety department does not allow us to apply the stress coat ourselves but we are allowed to bring in a third party to apply the stress coat. As a matter of fact, we have 4 machines being coated right now for loading tomorrow. The company we use is All Test & Inpection (http://www.alltest.com/) located in Blaine, MN. They do travel to various areas around the world for testing. Give them a call. Maybe they can help you out. As far as what is up with Stress Coat the company...the owner recently passed away. All Test purchased all of the remaining inventory from what I understand. I don't know if they will be selling materials or strictly the service of stress coating. As far as I know, there is not a replacement in the market place.
Hope that helps.
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Rank: New User
Groups: Member
Joined: 1/15/2008
Posts: 2
Points: 6
Location: Saskatoon, Canada
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Thanks
I'll contact them. It would be a shame if this stuff disappeared. It is unpleasant and difficult to use, but it is the easiest thing to use on large structures.
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Rank: New User
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Joined: 7/24/2008
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Location: Alabama
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Rank: New User
Groups: Member
Joined: 1/9/2008
Posts: 7
Points: 27
Location: UK
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I think here in UK StressCoat was 'banned' due to health and safety - some mention of carcinogens etc.
The last lonk to VISHAY concerns Photo Elasitic Interferometry (good technique) but uses different tools - usually painting on specific coatings to create a surface costing with a reflective backing and rely on the stresses in the plastic coating showing up as interference bands - we use it here at MIRA. You do not rely on 'cracking' the material.
I have heard rumours that there is a series of high quality varnishes used in the yachting world that have the same physical characteristics the StressCoat used to have, but you hav eot go thorugh a calibration process to know what crack line spacing (gradients) represent particular uE ranges. Possibly using a claibration bar.
I will trawl my notes and see if I can find a reference.
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Rank: New User
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Joined: 11/12/2008
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Location: Anglesea
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I use stresscoat products and the company I work for has used it for over 40 years
It is still the best way of finding high stress areas and strain gauge locations
It is easy to use as long as you allow enough cure time (usually 24 hrs) but can be affected by humidity
A degree in Meterology would be an advantage to forcast what coating to apply for "cracking "the next day
I still have sufficient stock of brittle lacquer but now require coating and undercoat thinners and am also trying to locate
Stresscoat or an alternative supplier. It is hard to source anything from Australia
We did use some time ago a product called Crux brittle lacquer from Japan but not sure if they still exist but it wasn't as good
as Stresscoat
Have tried photoelasticity but is messy and time consuming so brittle lacquer was the way to go, also validates FEA modelling
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