Radiator repair - The 1947 - Present Chevrolet & GMC Truck Message Board Network

67-72williso · 09-23-2007, 08:57 AM

I have a small hole in an almost new radiator, close to the top of the tank. What is the best solder,flux and heat source for this repair?
Thanks, Willis

68gmsee · 09-23-2007, 09:32 AM

Unless you're an expert at soldering with high heat I would just take it to a radiator shop. Not that expensive to just solder a hole. They did mine for less than $30 a few years ago and they went ahead and vatted it.

Never tried the solder but I've tried several methods in the past and none seem to be a good permanent fix. I tried an epoxy once. The epoxy held up well for about 6 months but I had to crush the tube.

All in all, it was more work to save a few bucks than to have a pro do it.

Just my .02

retselgerg · 09-23-2007, 09:49 AM

a rad shop is your best bet but if you can see it, JB weld will fix it and never come back out...what ever you do do dont use stop leak or anything to that nature

cdowns · 09-23-2007, 12:04 PM

if the tank is leaking and not the tube and the tank is brass i'd just use lead/tin solder and flux cleaniing it real good the tank must be emptyedand gently use a proprane torch apply the solder

racerman85 · 09-23-2007, 01:54 PM

What we do is we use JB weld... It works (circle track) and hasnt given us any trouble.. I also use it on the radiators for motocross. Good luck!

oldsmobilekindofguy · 09-23-2007, 02:06 PM

this is a temporary fix but i know a guy who had a farm truck with a hole in the radiator and he used half a can pf copenhagen and it stoped the leak for a week or so

oldsmobilekindofguy · 09-23-2007, 02:08 PM

i was surprised it worked but it did
he also did it to an old grain truck that was on their auction and it lasted almost a month

Premium72 · 09-23-2007, 02:24 PM

30 buck to fix a .50 problem. i had one get banged up pretty bad , pretty good size hole in it. i took it out soldered her up and still driven it today a few years later. solder that bad boy!

neonlarry · 09-23-2007, 02:34 PM

I use silver solder on copper piping, so I think it would work fine on a rad tank. It will definatly hold the pressure.

Sweet72 · 09-23-2007, 05:02 PM

Attempting to solder a seam can be frustrating as the area where the old and new solder meet always seemed to leak for me sooner or later. A pin hole is much easier to solder. Make sure the area is CLEAN down to bare shiny metal and flux it well than use a little heat from a propane torch to warm the area just enough to get the lead/tin solder to flow and fill the hole.

67-72williso · 09-23-2007, 09:47 PM

Thanks for all the information, I think I`ll try soldering it one of these weekends. I gess i`ll try using 50/50 solder, that dosen`t need a lot of heat to flow.
Thanks, Willis

09-23-2007, 08:57 AM	#1
67-72williso Junk/Daily Driver Club Join Date: Feb 2004 Location: Manheim, PA 17545 Posts: 253	Radiator repair I have a small hole in an almost new radiator, close to the top of the tank. What is the best solder,flux and heat source for this repair? Thanks, Willis __________________ Daily Driver: 1970 C-20 400 sbc,sm-465,Dana 61 one ton SRW rear, 3.07 gears, locker. There are three kinds of people: those who make things happen, those who watch things happen, and those who have no idea what happened!

09-23-2007, 09:32 AM	#2
68gmsee Active Member Join Date: Jul 2007 Location: Centrally located between Houston, Austin and Waco. BCS area. Posts: 7,947	Re: Radiator repair Unless you're an expert at soldering with high heat I would just take it to a radiator shop. Not that expensive to just solder a hole. They did mine for less than $30 a few years ago and they went ahead and vatted it. Never tried the solder but I've tried several methods in the past and none seem to be a good permanent fix. I tried an epoxy once. The epoxy held up well for about 6 months but I had to crush the tube. All in all, it was more work to save a few bucks than to have a pro do it. Just my .02

09-23-2007, 09:49 AM	#3
retselgerg Registered User Join Date: Mar 2007 Location: Grundy Virginia Posts: 385	Re: Radiator repair a rad shop is your best bet but if you can see it, JB weld will fix it and never come back out...what ever you do do dont use stop leak or anything to that nature __________________ "OLE BLUE" Goodwrench 350, 5speed, Tilt, PS, PB, "some guys got into cars for money or girls but i got into cars because of the cars" -Jay Leno

09-23-2007, 12:04 PM	#4
cdowns Senior Member Join Date: Jan 2003 Location: daytonabeach Posts: 22,956	Re: Radiator repair if the tank is leaking and not the tube and the tank is brass i'd just use lead/tin solder and flux cleaniing it real good the tank must be emptyedand gently use a proprane torch apply the solder __________________ 71c-10 350/2004r/4:11 lowered3/4 longbed/dead by hurricane MEANING OF DEATH::::: SOMEBODY ELSE GETS YOUR STUFF DONT BELIEVE EVERYTHING YOU THINK TAKE MY ADVISE;I DON'T USE IT ANYWAY

09-23-2007, 01:54 PM	#5
racerman85 Registered User Join Date: Nov 2006 Location: Windsor, PA Posts: 318	Re: Radiator repair What we do is we use JB weld... It works (circle track) and hasnt given us any trouble.. I also use it on the radiators for motocross. Good luck!

09-23-2007, 02:06 PM	#6
oldsmobilekindofguy Registered User Join Date: Aug 2007 Location: Stratford,SD Posts: 296	Re: Radiator repair this is a temporary fix but i know a guy who had a farm truck with a hole in the radiator and he used half a can pf copenhagen and it stoped the leak for a week or so __________________ 1967 c-10 longbox project, check it out in projects 1969 c-10 parts pickup, twisted frame Daily driver- 1970 Olds delta 88, 2dr., 455, gotta love the big block

09-23-2007, 02:08 PM	#7
oldsmobilekindofguy Registered User Join Date: Aug 2007 Location: Stratford,SD Posts: 296	Re: Radiator repair i was surprised it worked but it did he also did it to an old grain truck that was on their auction and it lasted almost a month __________________ 1967 c-10 longbox project, check it out in projects 1969 c-10 parts pickup, twisted frame Daily driver- 1970 Olds delta 88, 2dr., 455, gotta love the big block

09-23-2007, 02:24 PM	#8
Premium72 Registered User Join Date: Sep 2005 Location: Villa Rica Ga Posts: 889	Re: Radiator repair 30 buck to fix a .50 problem. i had one get banged up pretty bad , pretty good size hole in it. i took it out soldered her up and still driven it today a few years later. solder that bad boy! __________________ WombatFire, Art-Design-MADNESS Follow My Build and Adventures on Instagram

09-23-2007, 02:34 PM	#9
neonlarry Registered User Join Date: Feb 2002 Location: Vacaville, CA Posts: 2,745	Re: Radiator repair I use silver solder on copper piping, so I think it would work fine on a rad tank. It will definatly hold the pressure. __________________ 70 C/10 Light Red 350/TH350, HEI, Duals w/40 series Flows, 91 seat, LED taillights 99 Pontiac S/C GTP, SLP Ram Air hood, GMPP Konis & springs 95 Neon ACR, MP PCM, AFX UDP, 3.0 CAI

09-23-2007, 05:02 PM	#10
Sweet72 Registered User Join Date: Nov 2003 Location: Alexandria, VA Posts: 1,534	Re: Radiator repair Attempting to solder a seam can be frustrating as the area where the old and new solder meet always seemed to leak for me sooner or later. A pin hole is much easier to solder. Make sure the area is CLEAN down to bare shiny metal and flux it well than use a little heat from a propane torch to warm the area just enough to get the lead/tin solder to flow and fill the hole. __________________ '72 GMC SWB C1500 Custom, frame-off in progress. 383 SBC, 9:1CR, Comp Cams XE262H, Scat internal balanced crank, Eagle SIR 6" rods, Keith Black dish pistons, Dart Iron Eagle 72/180 heads, Weiand Stealth intake, Stewart stage I water pump, Holley 4bbl vac sec, TH350 with B&M Shift Improver Kit. 12 bolt positraction.

09-23-2007, 09:47 PM	#11
67-72williso Junk/Daily Driver Club Join Date: Feb 2004 Location: Manheim, PA 17545 Posts: 253	Re: Radiator repair Thanks for all the information, I think I`ll try soldering it one of these weekends. I gess i`ll try using 50/50 solder, that dosen`t need a lot of heat to flow. Thanks, Willis __________________ Daily Driver: 1970 C-20 400 sbc,sm-465,Dana 61 one ton SRW rear, 3.07 gears, locker. There are three kinds of people: those who make things happen, those who watch things happen, and those who have no idea what happened!



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