I've been using the Dow 55 and have been very pleased with its performance.

From past experience, I've learned to take these things with the proverbial grain of salt.

When my name and reputation is on the line, I tend to stick with what I know works. When I don't know, I RESPECT the opinions of the professionals who have more experience than I do. Especially the ones where the pride in their work is easily evident. Experience is an expensive lesson and I value that.

What is written on paper sometimes doesn't clearly make sense as to what works in the real world. The Dow 55 my reduce the tensile psi as per the posted chart but personally, I can't say I have seen or heard of anyone having a problem with it. In fact, I've noticed that some o-ring seals seem to last longer than before. That is my personal "real world experience" with it.

The Dupont grease seems like good stuff. Maybe it's a great alternative for engine o-rings and seals. But if you try and get this point across by contradicting the positive experiences everyone has already had (for quite some time now) with the Dow 55; you might have a hard time getting people to take the advice seriously. No one wants to listen to "snake oil salesman tactics."

I personally don't think anyone has anything to worry about their dow 55'd o-rings in their engines.

This isn't a reproach of supertech or Hank. The grease has no experience and isn't a person. If Hank wants to continue using it then I could care less. The revelers that hold Hank in a position beyond reproach and demand others to do the same need to get out more.

The first post in this thread actually is a good example. Given the DC 55 is presented as the best and the supertech fan club jumping in to blame the chamfer instead, one can only wonder how many are out there.

Andy, I said I'd refrain from commenting on your posts but I think it's important for all who use this forum to understand exactly where you are coming from. You have no interest in passing along tidbits of information to those who need it. You are here for one purpose; to be as big an ass as you can. As others have pointed out this is not your first time playing this game.http://forums.pelicanparts.com/support/smileys/clap.gif

Share your half of the conversation if you want to air the dirty laundry. Otherwise remove the inflammatory post.

Thank you,

The first post in this thread actually is a good example. Given the DC 55 is presented as the best and the supertech fan club jumping in to blame the chamfer instead, one can only wonder how many are out there.[/QUOTE]

I don't think anyone is holding anyone "beyond reproach." I think people are getting good advice from professionals who have everything to loose if they gave out advice they didn't believe in. People pick who they ask for advice from who they believe is the most qualified. End of story.


I had to chamfer the holes in my own engine and without any previous knowledge that supertech recommended it.

It seems as if the chamfer is a simple design flaw that experienced people have been able to properly identify and improve. I don't see how any grease can overcome a mechanical shortcoming.

My experience is no case chamfer, using krytox grease and no blown orings. I can't say the same for folks losing orings and starting threads with DC 55. It's not so much a mechanical shortcoming with that perspective.

And here's the graph from manufacturer showing the loss of strength going from ~1250PSI to ~700PSI when using DC 55:

http://i458.photobucket.com/albums/q...ps13839b78.jpg

That's about all I have to share information wise. The last nugget of info on this topic...

Lindy, let's wrap up our business in private message where it belongs instead of spoiling the public thread.

The mystery is solved.
After spending nearly an hour on the phone with Bob Nelson, products application engineer for Dow Corning Corp., we now have the definitive answer to Dow 55 Molycote and Viton compatibility.
Bob says that the tensile strength reduction is part of the product design. Dow 55 has a proprietary agent that swells the o-ring after installation. This swelling reduces tensile strength and reduces compression set while increasing seal surface pressure. Compression set is the o-rings ability to maintain its shape during prolonged cycles of compression and relaxation. The lower the number the better the seal. Dow 55 (in all its formulas) accomplishes this process with no measurable deterioration to the o-ring.
He also noted that Dow 55 offers no capillary action (wicking) with regards to most engine lubricants (additives may vary its resistance) unlike the use of white grease in similar applications.

Given this new found explanation, it appears that Dow55 is the perfect compliment to Viton under our application.

Late information:

My earlier conversation with Bob was just confirmed via email from Dave Kraycsir that Dow 55 is compatible with all formulas of Viton but especially Viton A .

Dave Kraycsir - Technical Customer Service
Sr. Engineering Specialist
Dow Corning Corporation

In the end, I guess, it all adds up to how much tensile strength is required for the O-ring to do it's job and if Dow 55 reduces that level of strength to the point of failure. Evidently there is sufficient strength of the Viton O-ring, even when compromised by the use of Dow 55, for it to do it's job over the long haul. I would think that compression set (as you mention) would be critical to sealing around threads of a case bolt where the O-ring is distorted around the threads for an extended period of time.

Thanks Hank, OOPS; I'm mean Henry!

Yep, never doubted they would recommend it as stated in my previous post. Just the tensile strength issue when alternatives exist that don't have that negative effect.

BTW, what is the molykote reference in your conversation with Dow about? I thought we weren't talking about the molykote line per your previous posts.

Molykote?

Maybe a simple error?

If your bias wasn't twisting your perception, you might realize that Dow 55M is only mentioned once in Henry's post.
Most of the post speaks to Dow55 in general. My evidence for this is the statement

"Dow 55 (in all its formulas) accomplishes this process with no measurable deterioration to the o-ring.".

I've highlighted the important information for you.


It should be obvious to all that, lubricant, beveled holes and tensile strength is not what this is about for little Raggedy Andy.
What we have here is a want-a-be trying to stroke his ego by attacking the knowledge and experience of a consummate professional.
It’s a sad but common story in every profession. Monday morning quarterbacking.

Now from Andy, we're getting :" two experts at Dow lied", "an independent consultant PSP INC. lied" and "Henry's experience is a lie". What a friggen joke!!!

Relax and take a deep breath. I don't know what thread you're reading but I never said any of that. I'm only pointing out the fact that it reduces tensile strength of the seal. Dow says they think that property of their grease fine and intended. We obviously have people making more room for these weakened seals that are tearing by chamfering their engine cases in this specific application using this grease. These are facts. I'm sure their grease is just fine for awhile when you create a space large enough the seal isn't pressured such as how Henry does with all his engines. That seems to be the reality of the situation. The facts haven't changed and Henry is rightly looking for justification for continued use of the grease. He's doing his homework to comfort his clients which is great and the responsible thing to do. It might also be worthwhile for the community to consider exploring alternatives although that's my opinion that I'm entitled to it. I'm not afraid to try different approaches though as I'm not bound by tradition, habit or pride.

Enough is enough. Sorry OP, our forum wasn't always like this.