Clear vs Purple Primer?

Kengar · 10/15/2017, 06:06 PM

Any difference in quality of the joint?

I'm going to be joining some schedule 80 that will be visible, so aesthetics are important. Oatey makes a medium gray cement, that should blend nicely, but I want to make sure the clear primer will be okay to use with it.

Thanks.

BigT75 · 10/15/2017, 06:10 PM

Not trying to hijack your post what’s the difference between 80&40

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Kengar · 10/15/2017, 06:12 PM

80 is significantly thicker, stronger. It's gray, vs typical white for 40. (I also have some black 40 that will be visible, and plan to use the gray cement for that, too.)

BigT75 · 10/15/2017, 06:13 PM

Ok gotcha thanks for that info on the difference

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Lsufan · 10/15/2017, 07:02 PM

The clear primer will be fine to use. I don’t think there is a difference in quality. The reason it is code in most places to use the purple primer is so inspecters can easily see that primer was used.

NanoReefWanabe · 10/15/2017, 07:04 PM

The clear is fine... but there is very little point in using sch80 unless you are running high pressure pumps... they be be thicker and stronger but they are considerably more restrictive

billdogg · 10/16/2017, 06:54 AM

^^^This^^^

And fwiw - I haven't bothered with primer in 20+ years - Our systems are very low pressure and really don't need it. I find that it just makes a mess.

ca1ore · 10/16/2017, 07:38 AM

Yep, primer-free here too. Cracked a few fittings, but never had a solvent welded joint fail.

mcgyvr · 10/16/2017, 08:16 AM

No difference in the clear vs purple except a dye.

And yes the ONLY reason for sch80 is because you are concerned about the color and want gray and don't want to paint it or purchase colored SCh40 (which is readily available now)..
There is no other valid reason as the pressures are never an issue in this hobby..

Kengar · 10/16/2017, 08:23 PM

Quote:

Originally Posted by NanoReefWanabe

The clear is fine... but there is very little point in using sch80 unless you are running high pressure pumps... they be be thicker and stronger but they are considerably more restrictive

for color. also, some of the fittings -- given size and specific configuration -- were only available as schedule 80 (from McMaster Carr).

saf1 · 10/17/2017, 05:49 PM

Sadly I lightly sand both parts making the connection, then use the purple primer on both, then let dry a bit before adding the glue. I then make the connection, hold firmly, then twist 1/4 turn to align properly and hold. Then done. All while wearing some form of latex type disposable glove. Same I use while wrenching on my car or painting. Makes cleaning up so much easier.

But yeah - lots of ways to skin the cat. Interesting enough there was an earlier thread about using tape, etc. I failed in that department I guess because I do use Teflon tape and it seems more and more recommend Oatey Great White stuff. I'm going to have to pick some of this stuff up I guess.

Diokhan · 10/19/2017, 05:13 AM

sch 40 vs 80 - sch 80 has a thicker wall than sch 40 - for pipe the od is constant and the id is thicker on sch 80. On fittings it's the opposite, the id is constant and the od is thicker on sch 80.

You can get sch 40 in gray. It's the same color gray as sch 80. You can still use the sch 80 fittings, which is nice as they are much beefier so you won't ever have to worry about breaking one. Quality valves only come in sch 80, so everything will still match for you.

I use weldon 711 on gray and 705 on anything else that I don't want see the excess that pushes out.

Please use primer. It softens the mating surfaces for the bond to penetrate. In fact, pvc solvent is basically primer with a filler added to account for gap filling in the bond. You'll get a better leak-free bond that way. (not recommended, but pvc will bond with straight primer, crazy!) No reason to use purple since primer also comes in clear and you aren't doing any requirements for building codes.

10/15/2017, 06:06 PM	#1
Kengar Registered Member Join Date: Sep 2000 Location: Gaithersburg, MD (D.C. Metro Area) Posts: 1,970	Clear vs Purple Primer? Any difference in quality of the joint? I'm going to be joining some schedule 80 that will be visible, so aesthetics are important. Oatey makes a medium gray cement, that should blend nicely, but I want to make sure the clear primer will be okay to use with it. Thanks. __________________ Resident Patent Attorney

10/15/2017, 06:12 PM	#3
Kengar Registered Member Join Date: Sep 2000 Location: Gaithersburg, MD (D.C. Metro Area) Posts: 1,970	80 is significantly thicker, stronger. It's gray, vs typical white for 40. (I also have some black 40 that will be visible, and plan to use the gray cement for that, too.) __________________ Resident Patent Attorney

10/16/2017, 06:54 AM	#7
billdogg Registered Member Join Date: Apr 2008 Location: Grove City, Ohio Posts: 10,806	^^^This^^^ And fwiw - I haven't bothered with primer in 20+ years - Our systems are very low pressure and really don't need it. I find that it just makes a mess. __________________ I'll try to be nice if you try to be smarter! I can't help that I grow older, but you can't make me grow up! Current Tank Info: 120 mixed reef with 40b sump, RO 150 skimmer, AI Sol Blue x 2, and a 60g Frag Tank with 100g rubbermaid sump. 2 x Kessil A360w lights, BM curve 5 skimmer

10/16/2017, 07:38 AM	#8
ca1ore Grizzled & Cynical Join Date: Apr 2006 Location: Stamford, CT Posts: 17,319	Yep, primer-free here too. Cracked a few fittings, but never had a solvent welded joint fail. __________________ Simon Got back into the hobby ..... planned to keep it simple ..... yeah, right ..... clearly I need a new plan! Pet peeve: anemones host clowns; clowns do not host anemones! Current Tank Info: 450 Reef; 120 refugium; 60 Frag Tank, 30 Introduction tank; multiple QTs

10/16/2017, 08:16 AM	#9
mcgyvr Registered Member Join Date: Sep 2003 Location: North Carolina Posts: 20,050	No difference in the clear vs purple except a dye. And yes the ONLY reason for sch80 is because you are concerned about the color and want gray and don't want to paint it or purchase colored SCh40 (which is readily available now).. There is no other valid reason as the pressures are never an issue in this hobby.. __________________ Who me?

10/15/2017, 06:10 PM	#2
BigT75 Registered Member Join Date: Jul 2017 Posts: 235	Not trying to hijack your post what’s the difference between 80&40 Sent from my iPhone using Tapatalk

10/15/2017, 06:13 PM	#4
BigT75 Registered Member Join Date: Jul 2017 Posts: 235	Ok gotcha thanks for that info on the difference Sent from my iPhone using Tapatalk

10/15/2017, 07:02 PM	#5
Lsufan Registered Member Join Date: Nov 2013 Location: Baton Rouge Posts: 1,410	The clear primer will be fine to use. I don’t think there is a difference in quality. The reason it is code in most places to use the purple primer is so inspecters can easily see that primer was used.

10/15/2017, 07:04 PM	#6
NanoReefWanabe Registered Member Join Date: Oct 2006 Location: Barrie, Ontario, Canada Posts: 6,639	The clear is fine... but there is very little point in using sch80 unless you are running high pressure pumps... they be be thicker and stronger but they are considerably more restrictive

10/17/2017, 05:49 PM	#11
saf1 Registered Member Join Date: Aug 2001 Location: California Posts: 2,259	Sadly I lightly sand both parts making the connection, then use the purple primer on both, then let dry a bit before adding the glue. I then make the connection, hold firmly, then twist 1/4 turn to align properly and hold. Then done. All while wearing some form of latex type disposable glove. Same I use while wrenching on my car or painting. Makes cleaning up so much easier. But yeah - lots of ways to skin the cat. Interesting enough there was an earlier thread about using tape, etc. I failed in that department I guess because I do use Teflon tape and it seems more and more recommend Oatey Great White stuff. I'm going to have to pick some of this stuff up I guess. __________________ -saf1 Current Tank Info: 210 gallon mixed reef

10/19/2017, 05:13 AM	#12
Diokhan Registered Member Join Date: Nov 2009 Posts: 22	sch 40 vs 80 - sch 80 has a thicker wall than sch 40 - for pipe the od is constant and the id is thicker on sch 80. On fittings it's the opposite, the id is constant and the od is thicker on sch 80. You can get sch 40 in gray. It's the same color gray as sch 80. You can still use the sch 80 fittings, which is nice as they are much beefier so you won't ever have to worry about breaking one. Quality valves only come in sch 80, so everything will still match for you. I use weldon 711 on gray and 705 on anything else that I don't want see the excess that pushes out. Please use primer. It softens the mating surfaces for the bond to penetrate. In fact, pvc solvent is basically primer with a filler added to account for gap filling in the bond. You'll get a better leak-free bond that way. (not recommended, but pvc will bond with straight primer, crazy!) No reason to use purple since primer also comes in clear and you aren't doing any requirements for building codes.