tap a vent

Claude

I'm fixing a radiator my friend gave me to use in my kitchen. Unfortunately the vent is broken inside the tap of the radiator. What size tap do I need to purchase to retap the hole? Thanks.

Unknown

air tap

1/8 NPT(27Threads per inch, tapered) Use a 11/32 Drill.

If you have to drill larger, tap 1/4NPT a(18 threads per inch, 7/16 Drill) and use a 1/4x1/8 Black Bushing.

Steve

Robert O'Connor_7

Threads broken off inside?

Why don't you just extract the old threads from the radiator?..Robert O'Connor/NJ

Matt Undy

yes, use an easy out/screw extractor...if that doens't work then drill it out..much better and safer to just take out the broken piece if it will come.

Matt

bob young

THREAD EXTRACTORS

IF YOU USE AN EASY-OUT TO REMOVE A BROKEN AIR VALVE FROM A CAST IRON RADIATOR, YOU WILL BE LOOKING FOR A REPLACEMENT RADIATOR IMMEDIATLY.

Matt Undy

Why is that? I'm not saying it isn't true, just if you say something like that without explaining why it doesn't help anyone much.

Matt

bob young

THREAD EXTRACTORS

AN EASY OUT WILL MAKE A HAIRLINE CRACK IN THE RADIATOR TAPPING , YOU MUST CHOP OUT OR DRILL OUT THE BROKEN THREAD. DO NOT USE EASY OUTS ON CAST IRON OR YOU WILL NEED A NEW RADIATOR OR BOILER OR WHATEVER.

Robert O'Connor_7

bob young.

Did you have a bad experience once Bob? Been doing this since 1971 and haven't broke one (air vent tapping) yet. I have however malded a few and had to tap them, but most success comes with resonable skill and dilegents, and a little bit of patiences...Robert O'Connor/NJ

bob young

EASY OUT----NOT

MATTER OF FACT I DID HAVE A BAD EXPERIENCE IN THE EARLY SIXTIES WHEN I USED A COMBINATION TAP EASY-OUT TO REMOVE A BROKEN AIR VALVE. . FROM A RADIATOR FOR A JOB FOR MY BOSS. COST ME THE PRICE OF A USED RADIATOR [ ABOUT FOUR OR FIVE BUCKS IN THOSE DAYS ] BUT I DID NOT FORGET THE LESSON. OVER THE YEARS I HAVE REPLACED SEVERAL BOILERS WHERE AMATUER MECHANICS HAVE CRACKED THE IRON ATTEMPTING TO REMOVE BROKEN GAUGE COCKS ETC. IFB YOU WISH TO CRACK A RADIATOR --BE MY GUEST AND USE AN EASY OUT . IT MIGHT WORK ONCE IN A WHILE SINCE YOU SAY YOU HAVE DONE IT, BUT I MYSELF WOULD NOT ROLL THE DICE . I DO NOT LIKE THE ODDS. AND AFTER FORTY + YEARS IN THE TRADE I HAVE DONE MY SHARE OF RISKY STUFF, MOSTLY SUCCESSFUL. ALL I CAN SAY IS " BEST OF LUCK. "

Claude

Home Depot had the tap and it worked for me nicely. I drilled it out with the 11/32 and then tapped it. The tap came out with the tread of the vent wrapped aound it like a spring. What do I use for paint? I don't care about color. Just wan to use the right stuff. I can't find a high heat primer. Auto store or paint store. So I'm at a stand still with my project. Thanks for all help. This board is great!

Mike T., Swampeast MO

Most common paints can handle the temperature of a water radiator--steam gets a bit "iffy".

If the current paint/coating is in VERY good shape you can use latex paint, but oil-based coatings are HIGHLY preferred and absolutely required if you're going over bare iron. As with any paint, if there is a thick buildup of layers and cracking has occurred, you need to remove the old paint. Sandblasting, a soak in lye and pressure washing (zero-degree nozele) are all effective methods.

If rust is showing through the paint, then latex was probably used and it must be removed and primed/painted with oil-based paint. Again, if the coating is in good shape--just dirty--do you best to clean. If you're pretty certain that the latex paint was used in the past then use latex--if you're fairly certain that it's only been painted with oil-based paint, then use oil. (When switching between oil/latex you can only switch once.)