Quote:
Originally Posted by robwijnstok
Hi Fidel,
Perhaps you will be followed sooner than you think. I have visited the website of Poxilina, and it is very interesting if my metal thermostat housing project proves to be undoable for me. I am following a dual line on the moment, and investigate on both Kaisers and you solution.
On the Poxilina site I saw at the specs that the maximum temperature is 80 degrees Celsius, so I am afraid that the engine temp while riding slow in city’s or in traffic jam’s will be a bit on the high site. I have dropped them an email if they have also other more heat resistant stuff. No reply yet, so I’ll be waiting for that now.
When your modified thermostat was fitted I recon you kept an eye op it from time to time. How long in km/miles and time ago did you fit it, and how does is look now? Is it heat resistant enough? And are there any tip and tricks when using this stuff?
Rob.
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Hi Rob,
It is obvious that a metal housing would be the recommended solution, but due to the complicated shape I decided to abandon the idea and to try this improvisation which was very cheap and not time consuming. I know that the epoxy compound is used somewhere around it's limits if not beyond it, but even if it fails it will not do any harm. No idea in what temperature range it is actually working, it depends on the plastic case thermal resistance and the only test I can do is to estimate the temperature touching the components of the cooling system with my hand. It may be above 80 degrees but definitely not above 100. No problems noticed by now except a slight smell under the bonnet when the engine is hot, but the reinforcing "belt" is only two months old, only time will tell if it will last or not.
A scientific approach would have been to include a small temperature sensor (an ordinary silicon diode) in the resin mass but, honestly, I didn't think about it at that moment.
That would tell how far the external temperature of the thermostat housing goes. Very easy to do it and if there is any member who has the time and the pleasure to experiment I will provide all the necessary information. The principle is very simple, based on the fact that the diode junction voltage is proportional with the temperature and increases by about 2 millivolt per Celsius degree.
I don't know what means their statement "POXILINAŽ withstands up to 80° C unaltered." According to my experience heated epoxy resins become slightly elastic when "cooked", returning to their normal state when cooled, if anything else happens in their chemical structure I don't know.
A better alternative is a special heat resistance polyurethane resin, it withstands up to 130° C if properly cured, but it comes in a liquid form, requiring a mold attached to the thermostat housing.
Whatever you'll chose to try feel free to ask any question, I'll try to help with any information within my knowlege range.