You can use a few methods.
I would recommend using fibre glass firstly and then maybe some sort of epoxy /putty.
FIRST AND MOST IMPORTANT
You will need to clean the areas that you are going to work with. And i do not mean like wipe with a tissue.
- I mean take some sand paper and lightly scratch the surfaces so it scores it to give better grip to the adhesive.
- You can do the same around the steel pipes you want to bond, but you will have to be more vigorous in making scratches in the metal.. this will help very much in bonding! It will not stick to flat surface very well.
- Try to work with gloves and avoid touching the area you are working with. Your fingers leave oily substance and can cause the bond to be weak.
- Using a clean cloth, spirits /alcohol (cannot be oily) clean the and blow out any dust residue, any particles from sanding, and wipe it clean with alcohol /spirits before you start to apply any methods.
- Make sure that during the cleaning and curing (drying period of at least 48hours) there is no water leaking in the affected area.
Fibreglass
You can buy fibre glass sheets pretty cheap, they are used in the boating industry, car body shops and some building supplies.
![enter image description here](https://i.stack.imgur.com/Vv8OW.jpg)
You will now clean the are and apply the fibre glass sheets in single layers, fold and mould them to the shape you desire.
During this process you will apply resin (it is very sticky so use gloves again) and dont be shy.. use plenty of it per layer.. let it dry a bit, come back and add another layer and expand over the bottom one. Maximise surface area.
![enter image description here](https://i.stack.imgur.com/wYedJ.jpg)
Here is an example on PVC pipe, patching up a leak. ON a steel pipe you need to wind it wider out to maximise the bonding surface, especially if its under pressure.
![enter image description here](https://i.stack.imgur.com/9KP5p.jpg)
Epoxy / Putty
Using a strong putty, usual called steel putty, or putty with steel, you will mix 2 compounds, or some tubs are air activated. So open them take what you need and close it.
![enter image description here](https://i.stack.imgur.com/Yf2z0.jpg)
You will mould the putty to the area you need.
![enter image description here](https://i.stack.imgur.com/uyrOc.jpg)
And you let it dry for the recommended period of time.
Pros / Cons
Because you are working with two different materials it is difficult to bond them. They both expand/contract in different ways and do not bond in the same way. Using either of the methods maximise the bonding effect.. while taking into consideration differential surface tension.
- These methods will bond and seal the two parts.. so if you ever need to get access to the pipes, maintenance or disassembly, you will most likely have to cut the steel pipe off with a grinder after the bondage leaving ample space for a connector later on.
It is possible that areas around the new bond might start to take the extra ware and tare.. monitor this and apply more fibre glass in areas that look like that might start to fail.
There is probably a gasket under that hold down flange. Buy a replacement gasket. Then remove the flange, use sand paper to remove any corrosion until you have a smooth, bright metal surface, then install the new gasket, and screw the flange back in.
Best Answer
Well those stupid infomercials would say to "wrap it in flex tape," don't do that, or wrap it in rags. (Fiber fix would be better then both, but please fix it properly.)
That looks like a copper compression fitting. As such just tightening it probably will not stop the leak. There is a small chance that will work, it may have just worked its way loose over the years so start by simply tightening it, a little. Do not over tighten it. After a compression fitting is tight over tightening it will only make it worse.
Unfortunately if it still leaks it is a bit of work. Turn off the water, open up the fitting and replace the brass compression ring in side there. The trouble comes in getting the old ring off. You will either need a compression ring puller or a compression ring cutter (a rotary cutoff tool can be used, but be very careful not to damage the pipe).
With the new ring on, tighten the fitting down it is about one turn after it makes contact.