Radiators now leak after powder coating

Luke Lefever_3

A customer of ours took the opportunity of a new boiler installation to remove several radiators and take them to be sandblasted and powder coated.  They look great.  So today, we fire up the new boiler  (NTI Lx 200), the system begins coming up to temperature, we go wandering around the house checking that all the air is bled out the coin vents, and the 5 radiators that they had blasted and coated are all leaking between sections.  Like leaking between every section.  So obviously they aren't very pleased right now.  I don't know what to suggest.  This is the first that we've ever known about radiators being powder coated- we've always had them blasted and then taken to an auto paint shop for paint.  I suspect that the baking process somehow was too much for the cast iron.  The radiators hadn't (until last week) ever experienced anything hotter than 215*F- the powder curing process I think exposed them to 450*F.



I suppose we could put some boiler dope in the system- but we'd need a different heat source (I'm not allowing dope into the new fancy-dancy boiler).



Suggestions?



Luke Lefever

Lefever Plumbing & Heating, Inc.

Elkhart, IN

<a href="mailto:luke@lefeverph.com">luke@lefeverph.com</a>

Unknown

Radiators now leak after powder coating

Are they push-nipple(using a "draw-rod") type?



Or the L&R screwed nipple type? 

[Deleted User]

leaking rads

Was thinking of the same process but the local coater that I contacted said the rads wouldn't take the heat of the process and would leak.



He had bad luck with CL rads.



That is the first that I have heard of this too!!

Luke Lefever_3

...

They are push nipple type- I talked to a local heating rep about them this afternoon and he's more of the opinion that they were handled too roughly by the powder coater than that the heat was too much.



I might bring one of them back to the shop and set up a little pumping station with an electric water heater to circulate hot water and boiler dope through it and see if we can seal it up.  Otherwise I think we're looking for new radiators.



Luke

Jean-David Beyer

Can they be rebuilt?

Can the defective push-nipples be replaced with new ones? I guess this amounts to rebuilding each radiator without messing up the powder coating.



Whether the labor cost of doing that would pay off or not, I would not know. But of those radiators have sufficient sentimental value to the homeowner, maybe that would be the way to go.

Unknown

Push nipple type,

is trying to tighten the draw-rods an option?

Luke Lefever_3

Tighten draw rods.

Maybe. I need to go to the site tomorrow and see what what my technician described for myself.



Luke

Unknown

Push nipple type,

IMO if you use some kind of "boiler solder" on a system served by a mod-con(no matter how well you flush the rad),, your problems will elevate higher.



Was the P/C your idea???,,, better start getting some signed documents as the boilers warranty will likely be null & void! 

Jamie Hall

Let us know...

but if they are draw rod with push nipples, there are two possibilities that I can see right away, neither good: first, the expansion from the heat stretched the rods (may be even broke one or two?), as the rods will cool much faster than the CI when the radiator starts to cool off.  This would let the sections separate.  Devil to get them back together.  The other possibility is man-handling the radiators (they don't like to be bent sideways) might have loosened things up.

Good luck!

Unknown

Tightening the Rods

    Jamie's scenario of the radiators expanding and stretching the rods makes really good sense.

 I wouldn't want to just try to tighten the existing rods as you'd probably break them.  I think I'd try 4 bar`clamps, two top, two bottom. I'd use 4 pieces of padded 2x4, one across the top and one across the bottom at each end of the radiator. The 2x4s would extend out a bit so you could put a clamp on each end of the 2x4 and connect it with the 2x4 on the opposite end of the radiator The bar clamps would then be tightened evenly and hopefully draw the radiator sections back together. After they were reasonably tight, you would then take up the slack in the rods.



I had a further thought -  If you don't have access to some bar clamps, they can be made up easily using a kit know as a PONY clamp. PONY clamp kits are available practically anywhere.  They  use a 1/2 or 3/4 inch pipe as a "bar" (I'd use the kit for 3/4 pipe)



You maybe able to tighten the radiators in place and that would save them getting knocked about further . Just an idea.

DanHolohan

Luke,

take a look at this part of the site: http://www.heatinghelp.com/article/21/Systems-FAQ/39/Radiators-Painting-Steam-Radiators



Scroll down to Dave's comment about paper gaskets and what can happen if the temperature gets too high during powder coating.

Dave Stroman

Push nipples

I sand blast and powder coat radiators a lot have not not had this problem.  There are no paper gaskets in these type of radiators.  It is unusual for all the sections to be leaking.  I have seen some radiators that were in a steam system where all the push nipples were rotten.  If these radiators were the Corto, or thin tube type, and they are only 3 or 4 tubes in width, they can not tolerate being laid on their side.  It will crank on the nipples and once the seal is broken they will never seal up again. 

You could replace all the push nipples, what a huge job that would be.  Any chemical you use in the system would be impractical because there is just too many leaks and would end up taking more time than just replacing the radiators and would probably not be a permanent fix.

Unknown

No paper gaskets?

I would most definitely wonder about that!



The "draw-rods" did the most,,, but the paper made-up for the subtle differences in machining & CI imperfections, perhaps you never saw that Dave, but they were there!

Luke Lefever_3

UPDATE!

Well, we sealed them.  We set up an old 30 gallon electric water heater with a Grundfos 15-58 circulating pump.  Bypassed the thermostat on the w/h to allow the radiator to get up above 160*F.  Wrapped radiator in foil faced duct wrap to keep it from dissipating heat faster than the w/h could generate it.  Put about .5 gallon of Hercules Boiler Liquid in it and let it heat up and circulate.  When the relief valve began to weep- turned off the circuit breaker to the w/h.  Repeat as necessary.  All 5 are re-installed in the home, running at system pressure on the new boiler, no drips.



Feeling a little lucky at this point.



Luke

Unknown

Well Done!

I don't want to say anything as this might jinx things but you get a BIG thumbs up for INGENUITY!!