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djkeev Samba Moderator
Joined: September 30, 2007 Posts: 32625 Location: Reading Pennsylvania
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Posted: Mon Aug 13, 2012 8:07 am Post subject: |
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First things first, an edit.....
The thickness of both clean bare bars clamped In the vise.... .257
OK, left off with Hylomar clamped in the vise using the same steel bars that were used for the ATV experiment........
[img]http://i1115.photobucket.com/albums/k554/djkeev/bff3ee7c.jpg[/
Here is a Photo of the Hylomar bars clamped in the vise and measuring in at .257, same as clean metal.
I removed it after "curing" and pried the same two pieces apart. Unlike the Red ATV you have to look close to find the blue film left by the Hylomar.....
I measured the Hylomar film, the anvil is on the back side so as not to mar the film with the rotating shaft of the micrometer..... A smidgen over .128 maybe .128333?
I then used lacquer thinner and cleaned the steel plate and measured in the same spot.... Again a smidgen over .128. Maybe .1282 ?
Conclusion? The Hylomar adds about .00025 to the case seam thickness (I doubled the .00013 because unlike the RTV which stuck upon one side of the steel and let go of the other side completely, the Hylomar evenly coated and stayed adhered to both pieces of steel.)
So current score...
Hylomar +.00025
Red High Temp RTV +.0005 / .001
Now using the same steel bars again........ testing the Permatex Aviation form a gasket Item #765-1210
I'll update once it cures......
What is it about the smell of this stuff? There is a peaceful pleasing aroma that brings back memories.......
Ok, Aviation clamped is .257, same as clean metal bars.
I didn't bother measuring by the aviation bars separated showed very little sealant on the surface.
On to Permatex Ultra Grey High Torque Sensor Safe RTV
Dave _________________ Stop Dead Photo Links how to post photos
Ghia
http://www.thesamba.com/vw/forum/viewtopic.php?t=392473
Vanagon
http://www.thesamba.com/vw/forum/viewtopic.php?p=6315537#6315537
Beetle
https://www.thesamba.com/vw/forum/viewtopic.php?t=482968&highlight=74+super+vert
Last edited by djkeev on Tue Aug 14, 2012 11:54 am; edited 1 time in total |
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UK Luke 72 Samba Member
Joined: September 07, 2011 Posts: 2867 Location: Little Britain
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Posted: Mon Aug 13, 2012 12:23 pm Post subject: |
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I'll bet your applying many times the clamping force and ACVW case half will ever see. I'm not a fan of hylomar due to the 'worms' you get on the inside of the case. |
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djkeev Samba Moderator
Joined: September 30, 2007 Posts: 32625 Location: Reading Pennsylvania
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UK Luke 72 Samba Member
Joined: September 07, 2011 Posts: 2867 Location: Little Britain
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Posted: Mon Aug 13, 2012 2:03 pm Post subject: |
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Good to see some quantitve results!
We shouldn't have to depend on people like you though, the manufacturers should have this info on hand. |
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scotth17 Samba Member
Joined: January 30, 2012 Posts: 335 Location: Bedford Texas
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Posted: Mon Aug 13, 2012 2:46 pm Post subject: |
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Why in the world are you prying the pieces apart and trying to mic sealer? Why not leave them together and measure the whole lot? no sealer thickness vs. with sealer thickness. And possibly more normal torque values... |
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djkeev Samba Moderator
Joined: September 30, 2007 Posts: 32625 Location: Reading Pennsylvania
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raygreenwood Samba Member
Joined: November 24, 2008 Posts: 21519 Location: Oklahoma City
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Posted: Mon Aug 13, 2012 5:36 pm Post subject: |
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You are going about this kind of backwards....but nice work either way!
I posted a link...maybe even earlier in this thread about how to get RTV's down to very thin levels.....BEFORE clamping. This is all about "shear" in application. I routinely...evry day...shear thin materials much higher in viscosity and tack than the permatex ultra series RTV's and with much higher solids contents.
By using a sheet of glass and a roller you first shear out and aerate (for much better curing) the RTV. This will yield a perfectly uniform coating typically in the 10-15 micron range.
Thats .000393" to .000590".
The interesting part is that even though that sounds tjicker than what you are seeing....under a side-lit mirror microscope....45% of that thickness or height is texture peaks. These peaks themselves tend to be about 6.7 microns in height....thats about .000255" in height over a fairly even bed of RTV that is about 7-9 microns in height....thats about .000315" thick.
This is the actual spread thickness. It can go slightly thinner but then you get down to the size of some of the solids particles in the RTV and the film becomes difficult to control.
Peaks and thicknesses this small are just fine enough to just fill surface imperfectiosn between moderately clamped surfaces ....and there is plenty of surface area to fill in even the finest machine work.
Typically the total addition to the gap between parts....is about .00015" to .0002".
For the record....there are 25.4 microns in .001". That means that .0001" or 1/10th of a mil.....is 2.54 microns.
Its all about pre-preparation and application technique.
Its also why I know for a fact that those who claim that RTV is dangerous and has no place in out engines are 100% wrong and simply do not know any other technique other than going the stuff on and slapping it together.
I am totally surprised the morons youspoke to at permatex have no idea of this especially since in their labs this technique would be one commonly used for film strength testing , viscosity and shear strength testing. I suggest you spoke to sales people an not technical people. Ray
Here is the link to the photo set.
http://s1186.photobucket.com/albums/z368/raygreenwood/RTV%20application/
When I originally posted this...I think I noted that the thickness read was about 1.75 mils. That was incorrect. The gauge pictured is direct reading in microns. It goes from 0-1 mil. I had two gauges and ended up using the finer of the two for the second roll out and application.. After the second roll and some tacking up......the final thickness was about .0001 or 1/10th of a mil...or about 2-2.54 microns.
The sharpy marker X's are so that you can see that the RTV is transparent. |
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djkeev Samba Moderator
Joined: September 30, 2007 Posts: 32625 Location: Reading Pennsylvania
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Posted: Tue Aug 14, 2012 12:09 pm Post subject: |
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Ray, thanks for the added input and photos of rolling RRV onto seams. You've got much better measuring tools than I do!
While your method of Rolling RTV using a printers roller us ideal, let's be honest Many? Most? Almost ALL? Will not use this method but will instead squeeze it out of a tube thinking "a little is good, more is better" thus creating engine killing globs in the crankcase!
I just did Permatex Sensor Safe Ultra Grey RTV Silicone.....
Here it is, clamped in the vise, I measure at several points and came up with very similar dimensions, this one shown is actually one of the thinner spots!
.2595
Compare this with clean metal thickness of .257 you've got a serious increase in size! .0025
Interesting how like the Red RTV, the Grey clung to only one piece or the other
Keeping with doing my separated measurements, here in the first photo is the micrometer showing .131 on the Grey Silicone and in the second photo showing .128 on clean steel. That's .003 of thickness when not compressed.
Dave _________________ Stop Dead Photo Links how to post photos
Ghia
http://www.thesamba.com/vw/forum/viewtopic.php?t=392473
Vanagon
http://www.thesamba.com/vw/forum/viewtopic.php?p=6315537#6315537
Beetle
https://www.thesamba.com/vw/forum/viewtopic.php?t=482968&highlight=74+super+vert |
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Max Welton Samba Member
Joined: May 19, 2003 Posts: 10697 Location: Black Forest, CO
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benchracer1 Samba Member
Joined: September 24, 2006 Posts: 583 Location: ramona
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Posted: Fri Oct 26, 2012 8:19 pm Post subject: |
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I have used gascacinch and aviation form a gasket for several years with good results. I recently discovered threebond 1211 and used it on some motorcycle centercases with great results. I saw where a few guys on this forum used it in vw apps. I am assembling a set of cb aluminum cases and would like to know if anybody has used this for a case halve application. I saw on a few posts where bros. Machine uses this product. Does any body know if they use it on centercases?.......Steve |
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Lebleboojian Samba Member
Joined: February 02, 2010 Posts: 56 Location: New Jersey
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Posted: Sun Jan 12, 2014 4:36 pm Post subject: sealer |
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So the big question is Permatex aviation sealer any good, will it leak? Or should I go with Curil-2? |
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modok Samba Member
Joined: October 30, 2009 Posts: 26788 Location: Colorado Springs
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Posted: Sun Jan 12, 2014 6:33 pm Post subject: |
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The permatex avaition goop is not very high tech but easy to work with and probably better than ketchup.
If you want it to be the last time it's ever taken apart then it may be worth using the fancier stuff.
Ketchup engine BTW, significant leaks form case studs to head, some at the cylinder spacers, hard to judge results of the case seam itself now since other leaks getting worse.
Speaking of that, i think I'll make a point to use only rimco spacers and the loktite teflon thread sealant on the lower studs and washers from now on. |
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Vanapplebomb Samba Member
Joined: November 03, 2010 Posts: 5412 Location: Holland, MI
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Posted: Fri Dec 05, 2014 6:29 pm Post subject: |
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Anybody use Permatex Motoseal? A guy recommended it to me today for sealing case halves. He said it is Permatex's version of Threebond fuji/honda/yamaha sealant. Just curious if anybody else has had experience with it and knows first hand how it holds up over time, or how it compares to Permatex Aviation form-a-gasket. _________________ 1800 Type 4 Berrien 295
http://www.thesamba.com/vw/forum/viewtopic.php?t=487021 |
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dcarlson12 Samba Member
Joined: May 04, 2014 Posts: 71 Location: Surrey, BC, Canada
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Posted: Wed Jun 22, 2016 12:47 pm Post subject: Re: Sealing case and cylinders? |
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When using Gasgacinch, how much do you apply? i.e. I guess you apply to each half of the case
Do you apply one coat, let it 'skim over' and then apply another coat or ? _________________ The 'caretaker' of my wife's 66 bug; her dream car. |
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wcfvw69 Samba Purist
Joined: June 10, 2004 Posts: 13389 Location: Arizona
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Posted: Wed Jun 22, 2016 1:24 pm Post subject: Re: Sealing case and cylinders? |
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dcarlson12 wrote: |
When using Gasgacinch, how much do you apply? i.e. I guess you apply to each half of the case
Do you apply one coat, let it 'skim over' and then apply another coat or ? |
A very thin layer on bath halves should be perfect. Only one coat is needed. _________________ Contact me at [email protected]
Follow me on instagram @sparxwerksllc
Decades of VW and VW parts restoration experience.
The Samba member since 2004.
**Now rebuilding throttle bodies for VW's and Porsche's**
**Restored German Bosch distributors for sale or I can restore yours**
**Restored German Pierburg fuel pumps for sale or I can restore yours**
**Restored Porsche fuel pumps or I can restore yours**
**Restored Porsche distributors or I can restore yours** |
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Busstom Samba Member
Joined: November 23, 2014 Posts: 3853 Location: San Jose, CA
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Posted: Wed Jun 22, 2016 10:38 pm Post subject: Re: Sealing case and cylinders? |
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dcarlson12 wrote: |
When using Gasgacinch, how much do you apply? i.e. I guess you apply to each half of the case
Do you apply one coat, let it 'skim over' and then apply another coat or ? |
For what it's worth, I've enjoyed fantastic results on about a dozen engines using two coats, from the 1980's to about 2004, when I built my last one. Zero leaks, ever, on about 12 engines.
I don't remember if my mentor told me to do that, or instructions on the can, or what. I cruised the garage looking for an old can, but couldn't find one...prolly nothing on there.
Anyway, I don't use the dauber on the lid, it's clumsy for painting sealant precisely around studs and thin lines. Instead, get a nice acid brush, you'll be way happier. By the time you brush around the full perimeter of the case, the starting point will flashed dry, so if you do left, right, left, right again, you only need to wait a minute or two before you drop the right half down on the left and start torquing.
I have two engines waiting to go together, and plan to use Gasgacinch as always.
That said, I don't see why one coat per half wouldn't work as well...I think I'll measure the dry thickness before my next builds. |
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pilottangocharlie Samba Member
Joined: February 24, 2017 Posts: 83 Location: Newcastle, OK
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Posted: Thu Apr 26, 2018 6:11 pm Post subject: Re: Sealing case and cylinders? |
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For those using Curil T to seal, how are you applying the sealant? Do you leave it as a bead along the middle of the mating flange? Do you apply around main bearing studs when case isn't set up for the o-ring seals?
I'm working on my first rebuild (40HP 1200) and really don't want leaks.
Please critique my application. I have since cleaned the case half and wanted to get input before sealing it again (long story where a stud had terrible threads).
_________________ Tyler |
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Max Welton Samba Member
Joined: May 19, 2003 Posts: 10697 Location: Black Forest, CO
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pilottangocharlie Samba Member
Joined: February 24, 2017 Posts: 83 Location: Newcastle, OK
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Posted: Thu Apr 26, 2018 6:28 pm Post subject: Re: Sealing case and cylinders? |
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Max Welton wrote: |
Looks like too much to me.
I use my finger in a nitrile glove to apply a very thin smear.
Max |
Thanks Max, this is what I need to hear and the reason for asking.
When I pulled the halves back apart it seemed the bead was just pushed to the inside of the flange. I am certain that isn't ideal. _________________ Tyler |
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raygreenwood Samba Member
Joined: November 24, 2008 Posts: 21519 Location: Oklahoma City
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Posted: Thu Apr 26, 2018 8:49 pm Post subject: Re: Sealing case and cylinders? |
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FAR too much. Really....paper thin coat..... pulled in from the inner edge.
The apply a "bead" thing is why people hate RTV.....or any sealant. THIN. Ray |
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