Thank you, Patrick. I was worried that it would look like I am tooting my horn, and that is not the case. 73, lh -------- Original Message -------- Subject: Re: [Utah-astronomy] Seeking suggestions for repairing RH dome Date: Tue, 6 Mar 2012 23:49:55 -0700 From: Patrick Wiggins <paw@wirelessbeehive.com> To: Larry Holmes <larry@kijoda.com> Hi Larry, Excellent thoughts. Please post them to Utah-Astronomy (or I can forward your post there if you like). patrick On 06 Mar 2012, at 23:32, Larry Holmes wrote:
On 3/5/2012 8:05 PM, Patrick Wiggins wrote:> The results of today's inspection of SPOC's Refractor House dome are not encouraging.> > Basically, water sprayed on the outside poured right through to the inside.> > Leaks everywhere and lots of them.
1. First of all, Patrick, is to decide just what you want to accomplish and how that end is to be achieved.
2. The next step is to determine the total square footage to be covered. This gives you a base to start from to estimate materials required, either by club members, or by a contractor. Any contractor worth his salt will double check the figures.
3. 90%+ of success of any job like this depends upon the degree of surface preparation. You could buy the most expensive material available, but if it is just slapped over the existing surface, it is due to fail prematurely.
4. In most cases, you are going to need a sand blast. It maybe only a "sweep blast", or the product used may call for "a white metal blast." It may need only a hand or power tool cleaning. The product used will determine the specific degree of cleaning required. One item, often overlooked, is a high pressure wash to remove not only surface contaminents, but more importantly, salt. If you just do a sand blast, any salt on the surface can just be driven into the surface profile left by the blast procedure. Then, if coated over, it leaves pockets which will eventually rust, leading to disbondment& again, early failure. There are additives to add to the wash water to aid in salt removal.
5. I might as well address a couple of theroems postulated in earlier postings: a) "You cannot bond fiberglass strips to metal" is hogwash, pure and simple, as is the notion epoxy will last just a year. The paints most used by such as KUCC, the salt plants around the Lake, water treatment plants, steel tanks for potable water (total immersion service), are epoxies. The other is the idea of depolymerization due to high summer heat. Once an epoxy cross- links, it will take temps on the order of fire to do that. Just look at UDOT's bridges--their spec calls for all surfaces not exposed to sunlight to be coated with epoxy. I know as I sold the coatings used by UDOT for some 10 years. The main downgrade to an epoxy for exterior coatings is that they are not UV restant and tend to fade in color rapidly.
6. My suggestion is to use a flexible, rubberized coating. Many could be applied by brush, roller, or spray. That would mean club members could apply if you are looking to save $$. But, if you want something on the order of a 50 year life (one posting states observatories are passe, so maybe you do not need that life, just perhaps 10 or 20 years). In that case, see #1). I totally agree with Dan. This needs to be done by a contractor.
7. You may question my bona fides. I have sold (and still do) industrial coatings for over 30 years. I have been a member of NACE (National Associan of Corrosion Engineers). SSPC (they set the standards of what constitutes a certain grade of surface preparation), PDCA. Sampe, as well as various other proffessional organizations. I still maintain a membership in WEUA, a fancy name for sewage plant operators. I am not, nor do I profess to be, an engineer. But, rust& corrosion is my business. I would be pleased to sit in on any committee, or what ever, to offer any help I can. This has been kinda wordy, but I had a lot to say, so I apologize for for the length. 73, lh
From the for-what-it's-worth department: I did not question the use of epoxy coatings, only the use of epoxy as a sealant. My experience (only 25+ years, and limited to construction, as opposed to Larry's 30) is with epoxy coatings and epoxy bonding agents for reinforcing steel, fiberglass and carbon-fiber fabrics, and similar uses. I do not know of any epoxy sealants that are made for the specific purpose that was posited, i.e. sealing a narrow joint in metal exposed to weather extremes. That's not to say that there are none - I just don't know of any. Conventional butyl, silicone or polyurethane sealants are more likely to perform adequately. I don't think that I said epoxies would only last a year, just that I didn't think using an epoxy that is not intended to perform as a sealant in this case would last. I've use the heat of a hair dryer to break apart epoxy bonds, but of course epoxies are not all created equal. I still think that the high temperature that the exposed metal dome could reach in summer as well as the resultant thermal movement itself could cause epoxies not formulated for this kind of service (e.g. must remain flexible) to fail. My fear was that we would just grab some off-the-shelf epoxy and try to use it as a sealant, and I was only warning against that. The key, as with any material, is to ensure that it fits the purpose for which it is intended.
Thanks, Larry for your thoughts. 'Nuff said. Kim out. -----Original Message----- From: utah-astronomy-bounces@mailman.xmission.com [mailto:utah-astronomy-bounces@mailman.xmission.com] On Behalf Of Larry Holmes Sent: Wednesday, March 07, 2012 10:07 AM To: Utah Astronomy Subject: [Utah-astronomy] Fwd: Re: Seeking suggestions for repairing RH dome Thank you, Patrick. I was worried that it would look like I am tooting my horn, and that is not the case. 73, lh -------- Original Message -------- Subject: Re: [Utah-astronomy] Seeking suggestions for repairing RH dome Date: Tue, 6 Mar 2012 23:49:55 -0700 From: Patrick Wiggins <paw@wirelessbeehive.com> To: Larry Holmes <larry@kijoda.com> Hi Larry, Excellent thoughts. Please post them to Utah-Astronomy (or I can forward your post there if you like). patrick On 06 Mar 2012, at 23:32, Larry Holmes wrote:
On 3/5/2012 8:05 PM, Patrick Wiggins wrote:> The results of today's inspection of SPOC's Refractor House dome are not encouraging.> > Basically, water sprayed on the outside poured right through to the inside.> Leaks everywhere and lots of them.
1. First of all, Patrick, is to decide just what you want to accomplish
and how that end is to be achieved.
2. The next step is to determine the total square footage to be covered.
This gives you a base to start from to estimate materials required, either by club members, or by a contractor. Any contractor worth his salt will double check the figures.
3. 90%+ of success of any job like this depends upon the degree of
surface preparation. You could buy the most expensive material available, but if it is just slapped over the existing surface, it is due to fail prematurely.
4. In most cases, you are going to need a sand blast. It maybe only a
"sweep blast", or the product used may call for "a white metal blast." It may need only a hand or power tool cleaning. The product used will determine the specific degree of cleaning required. One item, often overlooked, is a high pressure wash to remove not only surface contaminents, but more importantly, salt. If you just do a sand blast, any salt on the surface can just be driven into the surface profile left by the blast procedure. Then, if coated over, it leaves pockets which will eventually rust, leading to disbondment& again, early failure. There are additives to add to the wash water to aid in salt removal.
5. I might as well address a couple of theroems postulated in earlier
postings: a) "You cannot bond fiberglass strips to metal" is hogwash, pure and simple, as is the notion epoxy will last just a year. The paints most used by such as KUCC, the salt plants around the Lake, water treatment plants, steel tanks for potable water (total immersion service), are epoxies. The other is the idea of depolymerization due to high summer heat. Once an epoxy cross- links, it will take temps on the order of fire to do that. Just look at UDOT's bridges--their spec calls for all surfaces not exposed to sunlight to be coated with epoxy. I know as I sold the coatings used by UDOT for some 10 years. The main downgrade to an epoxy for exterior coatings is that they are not UV restant and tend to fade in color rapidly.
6. My suggestion is to use a flexible, rubberized coating. Many could be
applied by brush, roller, or spray. That would mean club members could apply if you are looking to save $$. But, if you want something on the order of a 50 year life (one posting states observatories are passe, so maybe you do not need that life, just perhaps 10 or 20 years). In that case, see #1). I totally agree with Dan. This needs to be done by a contractor.
7. You may question my bona fides. I have sold (and still do) industrial
coatings for over 30 years. I have been a member of NACE (National Associan of Corrosion Engineers). SSPC (they set the standards of what constitutes a certain grade of surface preparation), PDCA. Sampe, as well as various other proffessional organizations. I still maintain a membership in WEUA, a fancy name for sewage plant operators. I am not, nor do I profess to be, an engineer. But, rust& corrosion is my business. I would be pleased to sit in on any committee, or what ever, to offer any help I can. This has been kinda wordy, but I had a lot to say, so I apologize for for the length. 73, lh
On Wed, Mar 7, 2012 at 10:07 AM, Larry Holmes <larry@kijoda.com> wrote:
Thank you, Patrick. I was worried that it would look like I am tooting my horn, and that is not the case. But, rust & corrosion is my business. I would be pleased to sit in on any committee, or what ever, to offer any help I can.
If I could toot my own horn, I'd probably never leave the house! ;-) I'm a rather crusty old guy, could I be on the rust & corrosion committee too? Good, practical info Larry, thanks!
Chuck, I have mentioned to Bruce that you have the expertise that will be valuable in solving this problem. That is why I cc'd you on the email I sent to the supplier of the roof sealant product. I have also been following the thread about welding all seams on the dome. This might be considered but we would still need to seal the dome even with welding. If there is no differential movement between segments of the dome without them being welded, I think we could safely go with a good prep job, sand blasting etc. and then apply the sealant. The demographics of our group make it such that I would think that if we could afford to contract the entire thing out, that might be the way to go. With you offering to advise on this, I would love to have you as a participant on a steering committee to resolve this problem. Let me know. Thanks Rodger C. Fry -----Original Message----- From: utah-astronomy-bounces@mailman.xmission.com [mailto:utah-astronomy-bounces@mailman.xmission.com] On Behalf Of Chuck Hards Sent: Wednesday, March 07, 2012 10:54 AM To: Utah Astronomy Subject: Re: [Utah-astronomy] Fwd: Re: Seeking suggestions for repairing RH dome On Wed, Mar 7, 2012 at 10:07 AM, Larry Holmes <larry@kijoda.com> wrote:
Thank you, Patrick. I was worried that it would look like I am tooting my horn, and that is not the case. But, rust & corrosion is my business. I would be pleased to sit in on any committee, or what ever, to offer any help I can.
If I could toot my own horn, I'd probably never leave the house! ;-) I'm a rather crusty old guy, could I be on the rust & corrosion committee too? Good, practical info Larry, thanks! _______________________________________________ Utah-Astronomy mailing list http://mailman.xmission.com/cgi-bin/mailman/listinfo/utah-astronomy Send messages to the list to Utah-Astronomy@mailman.xmission.com The Utah-Astronomy mailing list is not affiliated with any astronomy club. To unsubscribe go to: http://mailman.xmission.com/cgi-bin/mailman/listinfo/utah-astronomy Then enter your email address in the space provided and click on "Unsubscribe or edit options".
Hi Rodger: I mentioned in my reply to Kim that the welding would only take care of the leaks between the steel gores themselves, and there were still other areas that would need to be addressed differently. Also that priming and sealing the welds afterwards is mandatory, or they'll just rust-out in a few years.. I'd be happy to help in any way that I can, time permitting, but I am probably not able to monkey-up a ladder to do the welding myself, anymore. I don't trust my balance. A bucket truck would be an enormous help, rather than scaffolding. And I agree that if the budget allows, let the pros do it. Is there a category for "Dome Repair" on Angie's List? ;-) On Wed, Mar 7, 2012 at 11:10 AM, Rodger C. Fry <rcfry@comcast.net> wrote:
Chuck,
I have mentioned to Bruce that you have the expertise that will be valuable in solving this problem. That is why I cc'd you on the email I sent to the supplier of the roof sealant product. I have also been following the thread about welding all seams on the dome. This might be considered but we would still need to seal the dome even with welding.
If there is no differential movement between segments of the dome without them being welded, I think we could safely go with a good prep job, sand blasting etc. and then apply the sealant.
The demographics of our group make it such that I would think that if we could afford to contract the entire thing out, that might be the way to go.
With you offering to advise on this, I would love to have you as a participant on a steering committee to resolve this problem.
Let me know.
Thanks
Rodger C. Fry
Chuck, Maybe we could talk the Utah State Prison to allowing a work release program for the convicts. Well if they helped enough we could even name it the Con Dome ;^) Rodger Fry -----Original Message----- From: utah-astronomy-bounces@mailman.xmission.com [mailto:utah-astronomy-bounces@mailman.xmission.com] On Behalf Of Chuck Hards Sent: Wednesday, March 07, 2012 11:45 AM To: Utah Astronomy Subject: Re: [Utah-astronomy] Fwd: Re: Seeking suggestions for repairing RH dome Hi Rodger: I mentioned in my reply to Kim that the welding would only take care of the leaks between the steel gores themselves, and there were still other areas that would need to be addressed differently. Also that priming and sealing the welds afterwards is mandatory, or they'll just rust-out in a few years.. I'd be happy to help in any way that I can, time permitting, but I am probably not able to monkey-up a ladder to do the welding myself, anymore. I don't trust my balance. A bucket truck would be an enormous help, rather than scaffolding. And I agree that if the budget allows, let the pros do it. Is there a category for "Dome Repair" on Angie's List? ;-) On Wed, Mar 7, 2012 at 11:10 AM, Rodger C. Fry <rcfry@comcast.net> wrote:
Chuck,
I have mentioned to Bruce that you have the expertise that will be valuable in solving this problem. That is why I cc'd you on the email I sent to the supplier of the roof sealant product. I have also been following the thread about welding all seams on the dome. This might be considered but we would still need to seal the dome even with welding.
If there is no differential movement between segments of the dome without them being welded, I think we could safely go with a good prep job, sand blasting etc. and then apply the sealant.
The demographics of our group make it such that I would think that if we could afford to contract the entire thing out, that might be the way to go.
With you offering to advise on this, I would love to have you as a participant on a steering committee to resolve this problem.
Let me know.
Thanks
Rodger C. Fry
_______________________________________________ Utah-Astronomy mailing list http://mailman.xmission.com/cgi-bin/mailman/listinfo/utah-astronomy Send messages to the list to Utah-Astronomy@mailman.xmission.com The Utah-Astronomy mailing list is not affiliated with any astronomy club. To unsubscribe go to: http://mailman.xmission.com/cgi-bin/mailman/listinfo/utah-astronomy Then enter your email address in the space provided and click on "Unsubscribe or edit options".
Letting the pros do it would eliminate a lot of liability issues if, heaven forbid, someone got injured from the club. I doubt the project will come even close to breaking the bank.
Hi Rodger:
I mentioned in my reply to Kim that the welding would only take care of the leaks between the steel gores themselves, and there were still other areas that would need to be addressed differently. Also that priming and sealing the welds afterwards is mandatory, or they'll just rust-out in a few years..
I'd be happy to help in any way that I can, time permitting, but I am probably not able to monkey-up a ladder to do the welding myself, anymore. I don't trust my balance. A bucket truck would be an enormous help, rather than scaffolding.
And I agree that if the budget allows, let the pros do it.
Is there a category for "Dome Repair" on Angie's List? ;-)
On Wed, Mar 7, 2012 at 11:10 AM, Rodger C. Fry <rcfry@comcast.net> wrote:
Chuck,
I have mentioned to Bruce that you have the expertise that will be valuable in solving this problem. That is why I cc'd you on the email I sent to the supplier of the roof sealant product. I have also been following the thread about welding all seams on the dome. This might be considered but we would still need to seal the dome even with welding.
If there is no differential movement between segments of the dome without them being welded, I think we could safely go with a good prep job, sand blasting etc. and then apply the sealant.
The demographics of our group make it such that I would think that if we could afford to contract the entire thing out, that might be the way to go.
With you offering to advise on this, I would love to have you as a participant on a steering committee to resolve this problem.
Let me know.
Thanks
Rodger C. Fry
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Send messages to the list to Utah-Astronomy@mailman.xmission.com
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If I understood correctly, Larry is proposing a coating for the entire surface, and I think that would be great. A coating such as that would be ideal after the welding. Larry can suggest a coating that would bridge any imperfections in the welding or other surfaces. As Erik just pointed out, having a professional do any or all of the necessary work reduces liability and should also give us the option of having good warranties on products and labor. Kim -----Original Message----- From: utah-astronomy-bounces@mailman.xmission.com [mailto:utah-astronomy-bounces@mailman.xmission.com] On Behalf Of Chuck Hards Sent: Wednesday, March 07, 2012 11:45 AM To: Utah Astronomy Subject: Re: [Utah-astronomy] Fwd: Re: Seeking suggestions for repairing RHdome Hi Rodger: I mentioned in my reply to Kim that the welding would only take care of the leaks between the steel gores themselves, and there were still other areas that would need to be addressed differently. Also that priming and sealing the welds afterwards is mandatory, or they'll just rust-out in a few years.. I'd be happy to help in any way that I can, time permitting, but I am probably not able to monkey-up a ladder to do the welding myself, anymore. I don't trust my balance. A bucket truck would be an enormous help, rather than scaffolding. And I agree that if the budget allows, let the pros do it. Is there a category for "Dome Repair" on Angie's List? ;-)
In the case that the club doesn't contract out the work, I can volunteer to monkey around on ladders and such. I'm still young and not afraid of heights and am experienced with rock climbing, ropes, and safety gear. I don't have any welding experience, but I'm sure I could handle a sand blaster and or a paint brush or roller. Josh
Even if the bulk of the work is contracted-out, I'm sure we can use your help. Thanks for volunteering! Rodger will be handing out assignments once we know what the pros can do for us, and what we can afford. On Wed, Mar 7, 2012 at 11:33 PM, Josh <mountaindrifter@gmail.com> wrote:
In the case that the club doesn't contract out the work, I can volunteer to monkey around on ladders and such. I'm still young and not afraid of heights and am experienced with rock climbing, ropes, and safety gear. I don't have any welding experience, but I'm sure I could handle a sand blaster and or a paint brush or roller.
participants (6)
-
Chuck Hards -
erikhansen＠thebluezone.net -
Josh -
Kim -
Larry Holmes -
Rodger C. Fry