Hi,

copper wire is coated twice if high reliability is requested because there are (a few only) pinholes and effects from air-bubbles and particles in any layer.

So the cheaper 1L - wire (one layer only) will give short circuits and arcing in the vicinity of metallic parts - one defect any 100m is sufficient to pose severe problems!

So how many bubbles do you have after mixing and vacuum degassing the epoxi-glass mixture, and how many are there that you did not expect because more gas is freed during curing?

Adhesion problem is not existing if cleanliness is preserved, best to coat with second layer with the first layer not fully cured.

RHABE

Hello All,

If the water being transported is potable water meant for human consumption I'd be very worried about dissemination of the glass particles into the water. Also, you will have to have this type of pipe lining material tested by a laboratory with the testing lasting several years to gain any sort approval such as from FM, UL and AWWA and in the USA, from the USEPA and state health departments, otherwise your product will not be officially sanctioned, thereby you wold have wasted your money and time. Also be careful what type of epoxy you would be using as a liner, especially in water main pipe that conveys water meant for human consumption. Yo also have to know the interaction of the epoxy with the water chemistry as well as with water treatment chemicals, especially chlorine residuals. Be prepared for a long test evaluation procedure from any government agency.

Just my 88 Cents worth....

Yes, it is possible, but it depends on other factors, pipe size, pipe geometry, access to name but a few.... if the water is 'potable', ie drinking water, contact the coating manufacturer to see if they have 'approved' products for this service, these are generally of the epoxy polyamide resin types. In order to try and reduce or avoid any 'outgassing' use 100% Volume Solids coating materials, and after mixing allow the mixed materials to stand, this allows the air that becomes entrained during mixing to escape, and allows the CO2 that the chemical reaction generates during its initial stages to escape. This period is often referred to as the 'induction time' or the 'residency period'. It is considered Good Working Practice to apply this system in 2 coats, however be guided by the manufacturers written Technical Data instructions.

Good luck,

Thank you. Paint manufacturers can submit certificates for drinking water, my only concern is whether the second layer of 500 micron shall peel out during transportation of the water due lack of adhesion. It is to understand that two layers shall adhere well.

Yes, it is understood that intercoat adhesion is to be an important property, if the coating manufacturers application procedures must be closely followed in order to optimise service life of the coating. My advice to you is to closely engage with the manufacturers Technical department, they will know and understand their product and its behaviour better than anybody else. They may advise you that it could be possible to apply the system in a single coat application. If you still have any doubts, ask them to supply a written insurance backed performance guarantee.... this may cost you a few more dollars, but focuses the manufacturers mind, and gives you peace of mind at the same time.

If you need any more assistance, please do not hesitate to ask.

There are many companies out there who reline water mains with fully approved materials for potable water use.

Look here

http://www.google.com/search?hl=en&safe=off&sourceid=gmail&q=pipe+lining+for+potable+water+systems&btnG=Search&aq=f&oq=&aqi=

edmund