Stop-gap "O" Ring Repair?

[minuteman62-64]

My spa has an old style (1980's) cast aluminum heater housing. The grove for the "O" ring that seals against the electric heater element is badly corroded - particularly the ridge that forms the inside circumfrence). See attached photo.

Last time (maybe 10 years ago) I repaired a small area with JB Weld. This time the damage is quite a bit more extensive, and I'm thinking another approach.

I'm thinking of putting a bed of high-temp silicone in the "O" ring groove and bedding a new "O" ring in the silicone and letting it set up. Then assemble, hoping the set-up silicone has filled the gaps and will maintain a seal.

I need to get 6 months to 2 years out of this repair before I either rebuild the spa or get a new one.

What do you think? Will it work?

 

[gm280]

Re: Stop-gap "O" Ring Repair?

WOW there is a lot of corrosion there. Have you thought about having it sand blasted first and then use your method for the repair? Reason I ask that is because once sand blasted, you could apply a chemical to hopefully stop further deterioration of the metal...and you also could rebuild the area again with the JB weld. Just an idea...

 

[oldjeep]

Re: Stop-gap "O" Ring Repair?

I wouldn't even bother with the o-ring. Just try some permatex gold in the oring area and the mating faces.

 

[rbh]

Re: Stop-gap "O" Ring Repair?

YIKES!
If the area around the o-ring is that pitted, the housing just might be ready to pop pin holes.
I bet heating the water and the calcium deposits plus dissimaler metals added up to one big electrolisis pit (not well grounded or anodes)

Kinda like flipping a coin, the ATV sealant will work, but for how long and then were is the next issue going to come from?

 

[minuteman62-64]

Re: Stop-gap "O" Ring Repair?

YIKES!
If the area around the o-ring is that pitted, the housing just might be ready to pop pin holes.
I bet heating the water and the calcium deposits plus dissimaler metals added up to one big electrolisis pit (not well grounded or anodes)

Kinda like flipping a coin, the ATV sealant will work, but for how long and then were is the next issue going to come from?

You should have seen the amount of calcium I dug out of there, yesterday and during the last repair. Aluminum housing, copper heating element, high temperature and water that has relatively high mineral content. What could go wrong

I'm guessing that's why the new ones are SS or PVC.

Believe it or not, it didn't look that much different 10 years back when I did the last "stopgap" repair. The housing is close to 1/2" thick and shows no sign of pin holes yet. I only want a littl more time till I get ready for a major overhaul (rotted wooden casing) or replacement.

 

[dingbat]

Re: Stop-gap "O" Ring Repair?

Copper and aluminum play well together. It is the high mineral (calcium) content is playing havoc with you. I would hate to see the bottom you’re hot water heater

Old repair trick. Use JB or marinetex to fill old o-ring groove. Coat new o-ring with Vaseline or grease and press into groove. Let set for a short period, remove o-ring, and let the material cure. Use o-ring seal during assembly and it will be as good as new.

 

[MTboatguy]

Re: Stop-gap "O" Ring Repair?

I would just go to the local spa shop and purchase a new one in PVC, won't be that much money and will not give you a problem.

 

[minuteman62-64]

Re: Stop-gap "O" Ring Repair?

I would just go to the local spa shop and purchase a new one in PVC, won't be that much money and will not give you a problem.

I'll be doing that when I renovate the entire spa. For now, I just want to get it back operating for the Spring/Summer/Fall months.

Appreciate the input. I'm going to try the hi-temp Permatex to start. If that doesn't work I'll try the technique of laying the "O" ring in JB to mold a groove.

 

[dingbat]

Re: Stop-gap "O" Ring Repair?

I'm going to try the hi-temp Permatex to start.

Why Hi-temp? Even your Walmart variety silicon is good for twice the temperature of boiling water (400F verse 212F)

 

[colbyt]

Re: Stop-gap "O" Ring Repair?

Any port in a a storm and I think it will work for you. At least for some time.

 

[minuteman62-64]

Re: Stop-gap "O" Ring Repair?

Why Hi-temp? Even your Walmart variety silicon is good for twice the temperature of boiling water (400F verse 212F)

Huh. I wasn't thinking of that. Yeah, if the temp. ever gets even to 212 F. the whole unit is probablyt toast.

What about 5200? I'll check the temp. specs. for that. Seems like 5200 would be just a step below JB, but without as much surface prep. required.

 

[rbh]

Re: Stop-gap "O" Ring Repair?

I do not know about 5200 working?
Something automotive that will expand and contract with temp changes may be more in order.

 

[minuteman62-64]

Re: Stop-gap "O" Ring Repair?

I do not know about 5200 working?
Something automotive that will expand and contract with temp changes may be more in order.

Looked at the 3M site. 5200 Fast Cure specifically states chemicals used in pools and spas may break it down. Regular 5200 not encouraging - including relatively low temperature rating.

I'll go with the automotive gasket stuff.

 

[minuteman62-64]

Re: Stop-gap "O" Ring Repair?

Well, here it is, new "O" ring bedded in the Permatex High-Temp RTV Silicone Gasket Maker. Why that stuff? I use it on the thermostat for my OB and had a tube on hand. If it doesn't work it will come off and I'll try one of the other suggestions.

Soon as my new thermostat is delivered I'll install the unit and fire it up to check for leaks.

Hoping for 1-2 years before I do a major rebuild or replace.

 

[MTboatguy]

Re: Stop-gap "O" Ring Repair?

Should not be any reason that won't work, that high temp stuff with easily hold up to the temps, I have used the red for lots of different things and it held up just fine.

 

[minuteman62-64]

Re: Stop-gap "O" Ring Repair?

Permatex High-Temp Red RTV Silicone Gasket Maker is now on my list of "good stuff." The spa heater repair has now been in service for 6 months with no problems. In addition, I've been using it as the gasket for my OB thermostat housing, since parts for my 30 YO motor are becoming hard to locate. That application has been going strong for 2+ years now.