KeithC

I'm in to buy the Viton kit for $277.

Jim,
Thanks for taking your time to explain all of this.

High Temp Silicone

UPDATED:

1. dgeesaman
2. DaveW
3. WNEC98
4. RX-8
5. LAracer
6. miatrx
7. wapelhj
8. CHAGAR
9. KeithC
10. ???

You know, when this thread started I was only trying to help inform the members on how different types of rubber products can be used for different applications. Every material has pros and cons. The trick is trying to find a material that outperforms others in a specific applications where the cons wont have a negative affect. I am just glad to be able to contribute something I know best. It is not very often I get to talk about rubber/silicone.

Down the road I will talk to my chemist to see if it is possible to coextrude silcone/viton. A Viton hose liner and a colored silicone cover. I think it is possible but I would need to invest in a new head for the extruder. That way you could have the benfits of fuel/oil resistance on the ID and the bright colors on the OD (This may take about a years development time). It is an interesting idea though.

Jim

RonKMiller

What was wrong?

Plenty:

1.It would split easily putting it over nipples, even if cut
with a hose cutter and razor sharp fresh blade. I got
two different sizes (can't remember what sizes but it
was what they recommended) Some of the areas on
the FD3S engine are impossible to reach without using
long, curved tip, needle nose hose pliers. Trying to
force the hose over those fittings with the pliers
would result in a split almost every try.

2.On the tight radius bends it would kink every time. I
ended up buying #1 springs and inserting them inside
the length of the radius to keep it from collapsing.

3.Here I am 3 years later, and on close examination
many of the bends that were NOT tight radius are
collapsing just from age. Some of the ends
have split at the nipples as well.

4.If I even think of taking a hose off and reinstalling it
will most likely split when I put it back on.

5.The walls were way too thin on the smaller id hose.

6.On the plus side it did ahere well.

I tend to be a little more observant than most shade tree mechanics when I look at engines and components.
I have 25 years of experience wrenching on airplanes.

I would never think of putting silicone hose in contact with oil or even near it.

I'll probably use Gates brand vacuum hose for the next job - unless of course I find something better. I KNOW for a fact it will be far better than the HT stuff, even if it is EPDM. Textile reinforcement goes a long way in my mind to making a much "tougher" product.

The main reason most of these kids want silicone hose is because they are bombarded with advertising in the car mags to bling up their engine compartments in pretty colors. Christ, they even slip it over hood prop rods... They are scared to use EPDM since the OEM Mazda compound specified in 1989 turned to stone after 6 or 7 years. It sucked. There are plenty of newer ozone and heat resistant EPDM compounds developed since then that will go ten years in our cars - no problem - and for 50 cents (or less) a foot. I mean - really, if its good enough for airplanes...

I have no problem with ANYONE making a HUGE profit on what you do for a living - I certainly do and never feel a bit of remorse. I just ain't going to pay $250 or so for a few feet of freakin' vacuum hose for a 12 year old car. Hopefully you can come up with a better formula at a reasonable price. I'm sure whatever you come up with will be quality, and quality is NEVER inexpensive.

Anyway - good luck on your new venture!

sicminded

i'm in for the 10th? for ~$277

pm'ing you with my e-mail and phone#

doing a rebuild on my car soon, will have this put on at the same time. sounds like a great product and alternative to silicone and to someone who wants to spend a little more for the best application.

thanks,
chris

High Temp Silicone

ok we are closed out with the 10 kits.

1. dgeesaman
2. DaveW
3. WNEC98
4. RX-8
5. LAracer
6. miatrx
7. wapelhj
8. CHAGAR
9. KeithC
10. sicminded

I will get in touch with everybody when they are ready.

Thanks,
Jim

High Temp Silicone

Ron,

EPDM is a great material for all sorts of applications. The water, ozone, coolant, steam, and weather resistance are second to none. Car manufactures use quite a bit of this material because it it relatively inexpensive and does a great job on windows, door seals, cooling systemsetc. The only 2 bad things about EPDM are the lower high temperature limit and the oil/fuel issue again. I wouldnt even think about using EPDM in a temperature application greater than 280ºF constant.

A test we use on EPDM or any elastomeric material for that fact, is ASTM D 573. The test is excellerated heat aging. What we do is the following:

Heat resistance, Test Method D 573, 70hours @ 212ºF
Change in hardness
Chane in tensile
Change in elongation

EPDM
+10 points in hardness
-25% in ultimate elongation
-25% in tensile strength

Nitrile
± 5 points in hardness
-20% Tensile
-40% elongation

For silicone we bump the temp to 437°F for the same 70hours, and Viton 527°F

Silicone and Viton are typically the same values but different temperatures.
+10 points in hardness
-20% in ultimate elongation
-20% in tensile strength

Oil resistance, Test Method D 471, 70hours @ 212ºF
Change in hardness
Chane in tensile
Change in elongation
Volume change

EPDM
Any points in change of hardness is acceptable
Any points in change of elongation is acceptable
Any points in change of tensile is acceptable
Any points in change in volume (swell) is acceptable

Nitrile
-5 to +10 points in hardness
-25% Tensile
-45% elongation
-10 to + 5% swell

Silicone
0 to -10 points in hardness
-30% Tensile
-30% elongation
0 to + 15% swell

Viton 70hours at 400ºF
± 5 points in hardness
-25% Tensile
-20% elongation
0 to + 5% swell

The above is from American Soceity for Testing materials volume 9.01

As you can see EPDM is not very good for heat applications. Can anybody really nail down what tempertures these hoses are being exposed to?

GodsOwnThunder

Suggestion/Question:

Instead of putting in tight radius turns, can't you instead put in straight lengths of tubing connected to u-shapped (or V, or L shapped) metal or plastic connectors? (See Pic.)

I am getting ready for a hose job myself and this is what I am thinking of doing. It seems to me after reading most of these posts that connectors - not hose - is the issue.

This solution may double the number of connections, but it should also eliminate the problems related to tight bends.

GodsOwnThunder

More thoughts on the above post.

If using a hard connector, there is no danger of collapse.
Even though there will be more connection points, the connectors used to connect two sections of rubber/silicone can be bonded together instead of zip tied to be sure the connection is permanent.

High Temp Silicone

What would really heal in the designing of vacuum hose would be the tightest radius per size.

3.5MM min radius?
4.0MM min radius?
6.0MM min radius?
8.0MM min radius?

KeithC

Any word on the group hose purchase.........

High Temp Silicone

just a quick update on the Viton progress. We have the raw materials mixed already. A "drop sample" has been provided to the lab for testing. We always send a sample to the lab after we mix the raw material to make certain it meets the specification. Once it has passed we will begin extruding the compound. The testing requires some 72 hours to complete. so that puts us in the late Friday or early Monday slot for production. Then it will be washed and cut to length.

If anybody has any questions, feel free to ask.

Jim

WNEC98

iTrader: (2)

Thanks for the update!

I am really looking fwd to making this upgrade.

DaveW

I'm still in! Thanks.

High Temp Silicone

ok fellas, the Viton is finished. We are cleaning and cutting to length as I type this. It looks like I will have extra 8MM and 4MM so far. I am very happy with the way this turned out. I will post later today on the totals of each size.

be in touch!

High Temp Silicone

If those on the list didnot get an email from me please get in touch with me.

Thank you

rzograbian

that looks like the hose that tri-point uses for their hose job. thats where i bought it from and its the same thing as that. it was way way cheaper than that though. i wont tell the exact price but it was under $100 for everything

High Temp Silicone

Well I promise you that it is not Viton if it is under $100. That would not even pay for the raw materials. I will call them though and find out what they offer. I found their page and saw some silicone hoses and t-bolts that look very similar to what we make.

High Temp Silicone

I am in the process of making an additional small run. We ended up with some extra 4MM and 8MM so I decided to fill the gap an run the 3.5MM and 6MM to make 5 additional kits if anybody is interested.

Those that have already paid, the items shipped this morning. Look for them in 1-3 days depending on where you live.

PVerdieck

FOUND IT!!!!!

I remember when this thread popped up. I printed out a comparison study a while ago, but couldn't find the link. Apologies if this has been posted already

Compatibility of Tubing Material with Hot Engine Oil

High Temp Silicone

That is an interesting report. Who made that? Somebody spent some time researching all the values for the materials. The only thing I would add to that is to remember about grades of materials. We can control the cost of the end product with fillers. The more filler, the cheaper the product. However it also means it will not be able to perform like the 100% base polymer compounds.

The high temp rating on the viton was low for a 100% base material. Remember Dupont makes different grades of viton as well (GF, GLT, GL, etc.)

Some of the sources listed are very expensive! The same kit from Omega was over $594.00! McMaster we already know is over $781.00.

I have to throw my .02 here on the timeline though. I can make Silicone "Dissolve" in fuel compounds in the lab in less than 100h. Therefore I cannot agree with the 5 year or less theory. My thoughts on this project were that if you are going to do this job, put something on you will never have to worry about again. Who knows if you will want your car in 5 years?

dgeesaman

iTrader: (7)

I just received my kit today. Wow, this is resilient stuff - the 3.5 mm (small) hose can be bent around to under a 1" radius, and when you bent it to the point of kinking I still think air gets by. I don't have any solenoids laying around here, but test fitting suggests that tie-wraps will not be necessary.

Color looks stock black.

I look forward to an evening playing with nipples

High Temp Silicone

Finally somebody that received a kit. You guys started to make me worry!

I tried to take some pitures of the radius bends but with my "yesterdays technology" camera, I cant get clear close-ups.

The wall thickness came out nice I think. I bet the first thing you noticed was the weight of the hose itself. Fluroelastomers are heavier than almost any other polymer.

Keep us informed, I would like to see the completed project.

Jim

rockshox

iTrader: (3)

High temp thanks for all the great tech info. if i didnt already have my car completely done in viton (the thick wall stuff) i would buy a kit.

i havent seen too much info on neoprene though. can you comment on its heat and hydrocarbon resistance? all our problems with the stock hose seem to be with hardening cracking due to heat, not splitting nor swelling.

High Temp Silicone

Neoprene is a good material. It has some oil, better than EPDM and silicone but not as good as Nitrile and Viton. Like I had mentioned one time before EVERY polymer has pros and cons. The cons for viton are the cost and the fact that it doesnt do well with Methyl Ethyl Ketone.

Neoprene
Pro's = good weather resistance, relatively inexpensive, good ozone resistance, moderate oil resistance

Cons= attacked by fuels and oils at elavated temperatures. Not recommended for temperatures over 250F.


Jim

miatrx

I got the viton hose today and am very pleased. The weight IS impressive as is the thick wall and resiatance to kinking. I took everything off for a hose job today and was horrified at the condition of the Silicone hose job. The Large hoses were very loose and seemed to be sweating oil!. There were several serious kinks too. Zip ties were not in good condition either in some cases. I will be using clamps for the Viton. Does anybody have a great source for clamps? The 3/8 and 1/2 inch clamps that I found at Lowes look ok. Any thoughts? Looks like I will be driving the daily driver Miata for a few days!

Tom