Need to Repair pin hole leak on my radiator

[otlski]

After roughening the outside, I would take a small diameter drill, maybe 0.050", and drill through and ascertain the thickness of the plastic. I would then determine what standard tap size would yield a thread pitch that gave me at least three/four turns within that thickness. Note: smaller dia and courser thread is more favorable as long as the three/four turn criteria is met. Run a tap drill through to open it up (do not go over-sized here). Tap the plastic for the determined thread. I would then use a slow cure epoxy to fill the hole, the thread area, and the outside area. Do not use a fast hardening epoxy as they generally are less strong. Be sure to mix the epoxy up in an excessively large batch so as to get the mixing ratio correct. The threads will give some inside "tooth" for the epoxy to adhere to, give shear resistance, as well as providing a longer path out. The longer path is more likely to get sealed at various points along the way. I have used variations of this method before.

 

[Soundguy]

I doubt that rad is thick enough to tap.

if it was a hole near the cap, you could stick an oring on a #6 screw and insert from inside, sticking thru, then add another oring and a nut..

But if you have a plastic welding kit.. I think I might try that, then cover it with a plastic specific epoxy. as said.. there are plenty better than just plain jb weld.

In the end.. no matter what repair I did. I'd monitor water every use...

 

[4570Man]

I have always used garden hose water, and in a pinch I have used pond water. Has this really hurt anything?

 

[GPintheMitten]

I have my doubts about it being thick enough to tap as well. But good idea if we're thick. I can't get to it from the inside.

A lot of good ideas guys. I will look for a plastic epoxy and try it from there. Thanks.

 

[Egon]

I'd consider sanding the flat area and around the sides, clean with acetone, spread a good compatible epoxy over the flat area and around the corner, cover with fiberglass cloth. Lay on several layers of cloth. If a screw is used make sure it is stainless steel and goes on top of one layer of cloth and under several successive layers.

Do a practice run on a small adjacent area first so you can determine if the epoxy will hold. A quick pass with a heat gun just before the epoxy is applied may be considered. When all is cured sand down & paint or put on some bondo, saind & paint.

The radiator level should be below the leak when the patch is done.

 

[GPintheMitten]

I do have some fiberglass cloth left over from a boat project. As long as the epoxy sticks it should hold.

I'll give it a shot in a few days. It's supposed to warm up a bit. Meanwhile, back to making sparks on my welding project.

 

[Egon]

I'd consider sanding the flat area and around the sides, clean with acetone, spread a good compatible epoxy over the flat area and around the corner, cover with fiberglass cloth. Lay on several layers of cloth. If a screw is used make sure it is stainless steel and goes on top of one layer of cloth and under several successive layers.

Do a practice run on a small adjacent area first so you can determine if the epoxy will hold.

you say boat repairs; you will probably have better ideas than most of us!

 

[otlski]

I doubt that rad is thick enough to tap.

Could be true; I don't know how thick to expect it to be. Do you think it is less than 0.090"? If it is in that neighborhood then it would yield 3.6 turns using a 4-40 thread.

 

[otlski]

double post

 

[Ford850]

Coolant flush? Uh, hmm. I guess it's time.

You live in Flushing, and you've never flushed your radiator.

 

[GPintheMitten]

^^^Like that.

 

[Ford850]

I've used JB Water Weld on plastic and it worked great. Read some of the reviews on that stuff... pretty amazing.

 

[Xfaxman]

Here is another option:   3M? Marine Adhesive Sealant 5200 Black, PN05205, 3 oz Tube, 6 Tubes per case

 

[Coyote machine]

Here is another option: **3M? Marine Adhesive Sealant 5200 Black, PN05205, 3 oz Tube, 6 Tubes per case

View attachment 452704

That stuff is killer! The 5200 is used when one plans to NEVER take it apart. The 4200 is for things that may have to come apart sometime in future. Either would work for your situation. I know, I've used it on my boat hull on thru- hull fittings.:thumbsup:

 

[Xfaxman]

That stuff is killer! The 5200 is used when one plans to NEVER take it apart. The 4200 is for things that may have to come apart sometime in future. Either would work for your situation. I know, I've used it on my boat hull on thru- hull fittings.:thumbsup:

Yep, I used the 5200 White to seal a punctured rubber CV boot 6 months ago and it sealed it good.

 

[JRobyn]

Distilled water is always a good idea for cooling systems. Tap water has chlorine, various minerals depending on your locale, and questionable pH, all of which can cause problems. Ain't no telling what might be in pond water! Some will advocate NEVER using any tap water, but I thinks it's fine, and have had no adverse experience, using tap water for flushing. But then drain as thoroughly as possible and do your final fill with pre-mix or antifreeze and distilled.

Also best to keep a little distilled around for battery top-ups.

- Jay

 

[newbury]

Another alternative to a screw would be a rivet (with a small glop of JB Weld) if the hole is big enough to get s small rivet in.

 

[skyhook]

That stuff is killer! The 5200 is used when one plans to NEVER take it apart. The 4200 is for things that may have to come apart sometime in future. Either would work for your situation. I know, I've used it on my boat hull on thru- hull fittings.:thumbsup:

Thats the stuff I was talking about, I would dab a little JB first, let dry, then cover with that.:thumbsup:

 

[skyhook]

double

 

[jenkinsph]

Here is another option: **3M? Marine Adhesive Sealant 5200 Black, PN05205, 3 oz Tube, 6 Tubes per case

View attachment 452704

I keep both the 4200 and 5200 on hand for my boat and it works great. I buy it in 10 oz. tubes for a caulk gun but a small tube as pictured above would be perfect for such a small repair.

The pressure against a pin hole would be a tiny amount and the 5200 is very tough to get off. I use a grinder where I have to remove it. As long as it will stick to the plastic compound you have a little dab will do ya.