Leaky Blank Bolts

Chris_L

As you can see from the attached photo, I am getting some dripping from the bolts in the blank plate of my residential steam boiler, which is about 30 years old.  I've tried tightening the bolts a couple times, but fear I'll damage the boiler if I go much tighter.  (The bolts are stainless steel if that matters.)

Can any of the pros out there tell me the correct way to seal these bolts.  Note that the only leakage is from the bolts themselves, and not around the circumference of the blank.  Should I take the bolts out and seal them with something?  Do I have to replace the gasket behind the blank?

Thanks,

Chris_L

Steamhead

If the leak doesn't stop

you'll need a new gasket. What make and model is the boiler? 

Chris_L

Gasket

Thanks for the advice.

The boiler is a Burnham 404B.  I have the manual, and gasket part number is 8036019.  But when I search online, I can't find it.  Has that part number been updated?

Steamhead

You might want to call Burnham

to see if it's available. If it isn't, one can make a gasket from stock sheet gasket material. 

Abracadabra

making a gasket

Not sure how others do it, but I'd take a sheet of gasket material like Steamhead says place it on the back of the plate.  Use a ball peen hammer to tap out the outline of the place and the bolt holes. If you tap enough you don't even have to use a knife.  The edge of the plate will cut out the gasket.

Chris_L

Once it warms up a bit...

I'll get a gasket and put it in...or make one if I have to.   Burnham referred me to a local supplier who didn't have the part number for mine, but has another I think might fit.  Once I have the old one out, I can check to see if it matches.



Thanks for the instructions on how to make the gasket.

Mike Kusiak_2

Alternate solution

Another possibility is to remove the current gasket and use automotive RTV silicone gasket sealant instead. Car manufacturers are now many times eliminating conventional gaskets entirely and just using the RTV in car engines.



I have had very good luck using it as it virtually eliminates seepage at the joint. Just remember to clean the surfaces well before coating both and assembling.

Chris_L

RTV Silicone

might be an easier solution than making a rubber gasket.  And since my 20-year old car is much less reliable than my 30-year old boiler, I have experience using it. 



Glad to know it works.  Thanks.

Long Beach Ed

Stainless Bolts

While stainless bolts don't rust they are much more brittle than steel.  In removing them, spray them for several days with Kroil (which is a professional strength Liquid Wrench) and rap them several times each day with a nice hefty hammer while spraying them. 



You want to do all you can to loosen the crud on them before taking a wrench to them.  If you break a stainless bolt they are a dog to drill out!



Clean the surfaces well with a drill-mounted wire wheel. 



If using silicone, follow the directions.  Usually I let it set up a half hour before the last tightening.  Tighten evenly in steps, like the head on an engine. 



Put the silicone completely around all the bolts, as well as on the bolts if the tappings go through the water jacket.