Automotive Print Protection or Camouflage?

This is how I received my PCM back after it got rebuild by a professional exchanger.

They used silicone caulk to fix the holes. They can probably use the link too.

Warranty void if tampered with seal?

Is this the product?

Yes, the soft clear part. I don't think the seal between the caulk and the premium product is done properly. The silicone is also less jelly when dry and not transparent.

It is just to avoid such result that I want to have something similar to the original.

Post #3 looks good to me.

Generally things are "potted" to protect the delicate electrical components from the environment (moisture or vibration) or to hide the identity of the circuit.

How they are produced can fill books.

Buy a tube of clear RTV for small repairs.

Google "potting compounds"

I prefer something liquid, like a 2 component mix that levels out and bonds with the existing material. I have no clue what is in it now. It is transparent, but very elastic. You can tear it apart without compromising the components. Jelly like but not sticky. I have googled for it, but the specs I find are not that clear to me and I cannot relate what is in there as base - PU - Epoxy - PE? It is slightly yellow green but very transparent. Thank you.

20 years ago, I would have said it is silicone. But huge advances in chemistry have outdistanced my knowledge of today's encapsulation materials.

My guess would be silicone, acrylic, urethane or epoxy not necessarily in that order. Order would probably be reversed due to cost.

Still, I'd use a non-acetic acid silicone. If it smells like vinegar it might corrode some of the more delicate electronics.

Automotive electronics usually use a silicone potting compound to protect the electrical components from moisture and vibrational damage. Silicone is exceedingly difficult to rework, but this is not likely a real issue in automotive applications as the rework procedure is usually to just replace the box or at least the circuit card. Virtually any RTV silicone compound should work fine. I would avoid that designated for kitchen and bath applications, but an automotive grade would be okay.

Hello,

The product is called Humi-Seal. It comes in commericial and Military Grades. For the extra bucks, use the "reallt good" stuff

HumiSeal is a brand name for an acrylic conformal coating. It is basically just clear acrylic enamel.

the product that you are looking for is an encapsulating resin and you should be able to source it from any of a number of suppliers of polyurethane resin suppliers

google "adiprene" and "vibrathane" which are the tradenames of two popular urethane

moulding formulations

regards from south africa

fred evans

Many encapsulating resins, expecially those referenced in your post, are the result of a 2 part system mixing an iso-cyanate such as 2,4 toluene diisocyanate with a polyol such as Castor Oil. They are also used for filling the voids in telephone cable junction enclosures, etc. Much caution must be used when working with them since the TDI is very hazardous especially in terms of skin contact, respiratory exposure.

Just because you may be working with a small quantity doesn't mean that you exposure potential has been reduced.

TDI is a cousin to MDI, the cause of Bophal!

the compound is referred to as potting compound. common Silicon caulk IS NOT appropriate and is often used by laymen because of its' ready accessability in the construction industry. Go to the following link to see various potting materials and thier specs.:

http://www.pottingsolutions.com/my%20site/Suppliers/ps_potting_compounds.htm

Silicone potting compounds are most frequently used. They offer mechanical protection and are water resistant. They don't stop water vapor which can diffuse through the rubber and condense on the electronics causing corrosion. The most important thing to remember is to NOT use the silicone caulking compounds found in hardware stores The curing agent for these materials is acetic acid. It will destroy your electronics. Use only electronic grade potting compounds formulated for your purpose.

One very soft product I once saw used by the phone company was a 2 part polyurethane based on castor oil. It was considered to be re-enterable. If you cut it then let it stick together again it would seal. The company that comes to mind for castor oil urethanes is CasChem corporation although with the changes in corporate names and ownership this may not be current.

And a big MOCA to ya.

I want to thank you all for the helpful information. I received a lot of good reactions, that I will go and explore further. For me this was a real jungle and thanks to you, I will be able to deal with the issue. My best regards to everyone. Lo.