Best epoxy for small pin hole in aluminum exchanger...

BobC

Use the 91% alcohol, it does not contain any additives. Good high test vodka works well also.

Bob

john p_2

Was using denatured alcohol but many people say acetone, as well as the distributors of the Belzona products...

Larry_52

Belzona recommends their own reducing product of course or Methyl Ethyl Ketone (MEK) to clean. As long as it does does not leave a film. Then they want you to torch it to remove any oils, then more cleaning with MEK.

Good luck,

I have actually used belzona to fill a cavity on a tooth in someones mouth while at sea. Funny story, when he made it ashore his dentist couldn't grind it out. He said whatever we put in his mouth is better than what he had.

icesailor

MEK or Acetone is the cleaner of choice.

There's a word for it, but I'll have to use the word "Slidey". Anything I construct using WEST, I usually put at least 3 coats of clear, slow set resin on the wood surfaces and three coats of Polyurethane. When doing the Epoxy, it is extremely difficult to do vertical surfaces. It always wants to run. To make it stiffer, you add fillers. You can't add fillers to clear if you want it to stay clear. But it must be stiff to work it into and on a vertical surface. You almost have to keep all working surfaces horizontal.

If you were trying to put that Epoxy on a vertical surface, and you didn't have the system Open to the atmosphere, you can build pressures that are positive and/or negative which will make that "Pimple" like that did.

An Epoxy trick we use is to use wax paper or clear plastic wrap over the patch if it is going to slide out of place or you want it to be smooth. If you use wax paper, don't use cheap. Get the name brand. There's more wax on the paper. With the cheap stuff, sometimes the paper sticks to the glue. If you want it to look smooth and pretty, use the plastic wrap. You can easily squeegee out a first coat and add a second one.

Fun with wood.

john p_2

Very excited to use this product or at least see it cure in an hour!

Harvey Ramer

icesailor said:

MEK or Acetone is the cleaner of choice.

There's a word for it, but I'll have to use the word "Slidey". Anything I construct using WEST, I usually put at least 3 coats of clear, slow set resin on the wood surfaces and three coats of Polyurethane. When doing the Epoxy, it is extremely difficult to do vertical surfaces. It always wants to run. To make it stiffer, you add fillers. You can't add fillers to clear if you want it to stay clear. But it must be stiff to work it into and on a vertical surface. You almost have to keep all working surfaces horizontal.

If you were trying to put that Epoxy on a vertical surface, and you didn't have the system Open to the atmosphere, you can build pressures that are positive and/or negative which will make that "Pimple" like that did.

An Epoxy trick we use is to use wax paper or clear plastic wrap over the patch if it is going to slide out of place or you want it to be smooth. If you use wax paper, don't use cheap. Get the name brand. There's more wax on the paper. With the cheap stuff, sometimes the paper sticks to the glue. If you want it to look smooth and pretty, use the plastic wrap. You can easily squeegee out a first coat and add a second one.

Fun with wood.

That would be a good idea, shrink wrap it and then inject the epoxy with a blunt syringe.

john p_2

Well, very disappointed with the Belonza product. Prepared the area as per the person (engineer, I believe) I spoke to at the distribution offices for NJ.

Removed the old Cotronics epoxy, sanded with 60 grit sand paper, cleaned with acetone and dried with heat lamp - infrared thermometer indicated 118 degrees. Place the aluminum block in a small vacuum to help remove any moisture and also hoped to pull in the epoxy a little bit.
Rep said 1 hour cure time I believe at 77 degrees. I placed epoxy on at 1:30 this afternoon and started the boiler at 6:30 PM. I believe it was the third cycling of the boiler the bubble and drip appeared. Ughhh

bmwpowere36m3

Fully cured in an hr? Time to think about a rivet or screw sandwiching a rubber washer and some rtv.

Larry_52

That sucks! I am surprised it failed so easily, I have seen it repair engine blocks running at 180degs at 12psi. How much is getting in the hole? Never had to do this as it already incorporates filler, how about reinforcing with a coated strip of Kevlar?

john p_2

There are two pin holes you can't see until blown up using a cellphone camera. The leak is filling a 2.5" pan that's maybe 8"X 8" in 6 to 8 hours so not too terrible. With these temps being near zero so often I prefer not to make any new holes or the ones I have bigger. I will give JB Water Weld next - short cure time.

icesailor

"" That would be a good idea, shrink wrap it and then inject the epoxy with a blunt syringe. ""

you don't have to do that. If you want to do what the OP is trying to do, add filler to make it stiffer. Between Mayonaise and Peanut Butter.

They make all kinds of serious Epoxy concoctions. For any application you can think of. Cleaning and reading the instructions are important.

I worked on the installations of large stationary power generating diesels where they had to shim equipment into perfect alignment. nce shimmed, they used Epoxy

Another Heatinghelp.com lock-up.

Why did you pull a vacuum to try to suck the epoxy in?

If you want to use vacuum for vacuum bagging, you don't pull the vacuum so it sucks the epoxy into the hole, Vacuum bagging uses atmospheric pressure to force the epoxy ONTO the surface.

Don't do anything exotic. Just clean it again, get it all off, do it over, use a heat lamp to keep it WARM!!. Not HOT!!!!.

Are you mixing enough and are you mixing it properly? I've never seen an Epoxy patch be so difficult.

john p_2

I thought I did everything perfectly, not sure what is going on...at a complete loss. The warmest it was with the thermometer was about 118.

icesailor

You said that you pulled a vacuum on the boiler. I told you that Epoxy runs easily before it sets. You have no idea of the power of a vacuum in the right or wrong hands.

If what you applied this last time or before is firmly adhered to the surface, and it still leaked. it must have not been set it there was a pressure or a vacuum inside.

Do it over. Be sure that the bottom drain on the boiler is open during the entire time. You don't have to sand back to the wood on the old patch. If the Epoxy base is solid, and you use the exact same brand of epoxy over it, it will stick. Clean out the places it leaked well, sand it, clean it, and slather another layer of epoxy on it. Make sure that the drain is open. Let it cure overnight. It shouldn't be able to be picked at with a utility knife. The longer it cures, the stronger the adhesive bond will be. Keep the site warm with a patio light and a 100 watt bulb, or a quartz light work lamp with a 250 watt bulb. Don't let the surface temperature get over 125 degrees. Try to keep it over 100 degrees but well under 125 degrees.

Tat Epoxy will work. I think that it was pressurized +/- while you were rushing it. If the problem is a vertical surface, hold it on with waxed paper and masking tape or duct tape until cured.

john p_2

icesailor

That's not normal. I've put Epoxy on all kinds of things and nothing ever acted like that. Not ever.

john p_2

I know, very strange....two different products too.

bmwpowere36m3

Too me it still looks like its applied way too thin... or it was mixed up too runny. Like icesailor said, think consistency of creamy peanut butter on vertical surfaces.

john p_2

If I had to guess it would be an 1/8" thick in the center and edges were feathered outward. This 1221 Belonza product has a 3 minute pot life!

icesailor

Unless you have the drain open at all times on the boiler, you can get positive or negative pressures that you have no idea are occurring.

Take an empty water bottle. Drill a small hole in the cap. Suck on the hole. You will be amazed at how little suction it takes to collapse the water bottle.

When you get a slow leak in a car tire, it will leak out until the tire is totally flat. Atmospheric pressure will push out every molecule of air. The pressure on the inside of the HX must be equal to the outside without any restrictions.

Larry_52

After seeing that pic, maybe fiber reinforcing the epoxy is a better approach.

icesailor

If you are that worried, go to a marine store and get some carbon fiber mesh tape. Cut it with some throw away scissors.

If you apply the Epoxy properly with no positive or negative pressures inside the boiler, it won't bubble up.

Epoxy is sort of idiot proof. Even idiots can be successful with it.

john p_2

You guys are good. Steve Kitchen from Belonza just left my house and that is exactly what he did, applied a mesh, let it set up for approximately 15 minutes and then reapplied another coat of epoxy.
Before all of that he used a MBX Bristle Blaster on the bare aluminum where the pin holes were located - looks a little like a hand held grinder with a wire wheel but the wires are bent on the end. they seem to put little divots into the metal for the epoxy to grab. Waiting at least till 9PM before turning the boiler on.

icesailor

I hope he applied it with no positive or negative pressure in the boiler,

SWEI

Had to go look that up. Kind of a mini needle scaler?
http://www.nortonsandblasting.com/nsbpowertool-mbxbristle.html

Larry_52

That's when you know the product is good, the rep or company can't believe it failed and come over to make it right! There is a reason they are so predominant in the marine and industrial industry. I always knew their product was superior, but with that kind of support I will go out of my way to use it now. They could have easily blown off a homeowner end user based on their customer base is larger industry.

BobC

A company like that is very rare these days.

When I was running the calibration department and my old employers we really were on a shoestring budget. We used to buy most test equipment used, I remember we bought a lot of stuff at Elli Heffrons in Cambridge.

One time I went down and bought some HP 400H AC VTVM's that were just a bit long in the tooth. Old gear like this almost always needs some restoration to work properly, I called the Boston office of HP and talked to one of their salesmen Keith Blackie), I told him I needed a manual for the 400H meter, he asked what serial number. When I told him the SN he told me that was from their first run of that meter.

Two days later he showed up at the plant with a copy of the manual. I gave him the nickel tour of the place and he told me not to hesitate to call him if I needed any help with resoring the meters.

He knew we were never going to buy any quantity of new gear but he also knew I might work someplace else in the future where i could influence buying decisions. He cast his bread upon the waters because he had faith in the industry and the people who worked in it.

Wherever you are Kieth, I hope you are having a great life, not many left like you.

Bob

SWEI

That kind of service was what made so many of us into huge fans of companies like (the old) HP and Tektronix.

Still have a couple of VTVM's here that get used ~once a month, BTW.

john p_2

Success! Was nervous all night and anxious to see if it held through the night but it is fine. Kudos to Steve Kitchen and the folks at Belzona. So nice to know of a company that stands behind their product as they do. I am in a position where I can and will highly recommend them. I will post pics later....

john p_2

Here are the photos of the epoxy done by the rep Steve Kitchen and also the tool used before applying any epoxy, the MBX Bristle Blaster.

bmwpowere36m3

Love using that air powered stripping tool... strips the undercoating or rust off cars real nice!

john p_2

Two days and no more issues...other than the occasional loud bang heard outside when the boiler fires, unsolvable I guess...

kcopp

It sounds like you need to have a combustion test done to ease the hard light-offs.

j a_2

What type of gas valve do you have….? Banging is absolutely,not good…But very fixable….Post the gas valve model number

john p_2

Combustion test was done multiple times and all is good- will post latest results , next post. Here is a pic of the gas valve -Honeywell VK8115V

john p_2

Here is the last combustion test results...

icesailor

But does it still light off with an explosion? It isn't supposed to do that.

john p_2

Intermittently makes a loud noise outside by the exhaust pipe and inside when the gas lights sometimes it has a flutter type of noise...I've had two contractors from this site to the house but couldn't determine what caused it or how to stop it from happening...They both did combustion analysis, which were both good. The gas utility came and checked gas pressure at the boiler and at the meter...this was a few years ago so I do not remember those numbers but they said were fine.

john p_2

UPDATE : Epoxy repair done last week is leaking again, ugh.

j a_2

Hay you gave it your best…You know the next step….sorry to hear that

Larry_52

Die grind the Aluminum hole and TIG it. I would run purge gas into the boiler as you weld the exterior while you close the root.

If the last patch didn't work no normal epoxy approach is going to be a solution.