hole saw lubrication for cutting aluminum tank

duncan

duncan

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right - update for those who kindly responded to earlier thread; overview for others!

Airtronic D2 ordered - plan is to fit Saturday........ /forums/images/graemlins/smirk.gif

Decision from previous thread etc is to fit new fuel pick up which means cutting hole in aluminum diesel tank

25mm hole, new bimetal cutter.

Original thread included the advice to use a little grease on the cutter to 'hold' the swarf; cutter blurb recommends using parrafin when cutting aluminum and of course I have a ready supply of diesel available...........

As I can get access to below where I wish to cut (through the tank sender) I propose to hold a greasy cloth below where I am cutting anyway so can I use a touch of diesel instead of parafin?
 
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As I can get access to below where I wish to cut (through the tank sender) I propose to hold a greasy cloth below where I am cutting anyway so can I use a touch of diesel instead of parafin?

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Sounds like a great recipe for cutting a hole in your hand.

if you can get access to beneath, tape something like a cloth to cover hole, plus enough to avoid material snagging in hole saw if it disappears through hole.
 
if it was me I wouldnt use anything ally will dissipate the heat from the cutter. but I wouldnt use a fast speed.You cut ally with a hacksaw without using anything, a cutter is just a rotary hacksaw.
 
ps if you can get in the tank sender hole can you get a vacuum pipe in?or if not can you fit a bit of tubing on the vac. one more reason for doing it dry.
 
Duncan,
For a one off job cutting in a confined space you are better off using just enough water for the coolant and avoiding the stinking fumes. Aluminium quickly clogs the cutting teeth unless lubricant/coolant is available. I use kerosene at work because I have found it works very well, but in a confined area I switch to water.
 
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if you can get access to beneath, tape something like a cloth to cover hole, plus enough to avoid material snagging in hole saw if it disappears through hole

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..... and then the saw does snag on the rag spins around at 700rpm, ally filings fly off all inside the tank. Not what is wanted.

If I may, what I would do, with certain success is to use grease, run a variable speed drill, VERY SLOWLY!!!!! When the drill and the cutter goes through into the tank fillings will drop from under. Now, to avoid these dropping I would use a piece of self adhesive sheet (sticky back plastic) stuck on the inside, loosely. It will not stick very well so you will need a carefull hand under it, the diesel will stop it from sticking properly. I think it will be unavoidable to get some bits in the tank but its no worse than what is already there, thats what the filters are for.
 
The purpose of the lubricant is two fold - 1 is to cool the cutter and the second is to lubricate it and in doing so prevent pick up of the base metal by the cutter. If you cut aluminium dry you will get aliminuim stuck to the cutter so do use some form of lubrication preferabely something like "tapping and drilling lubricant" which is more than just kerosene but if you cannot afford the couple of beer tokens to buy the correct stuff then paraffin or even diesel will do as you are only cutting one hole.

No matter what you do you will get some cuttings in the tank but your primary filters should take care of that.

One way to minimise the cuttings getting into the tank is to cut the hole in stages, removing and cleaning the cutter between each cut until you are almost through then put a screw driver or similar in the pilot hole and you should be able to "work" the disk out as the thin Metal holding it will fatigue and tear like a ring pull on a beer.

I still reckon a separate tank is the answer though as you would have problems "tee"ing in to you fuel line.
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"Artificial intelligence is no match for natural stupidity"
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OK - looks like slowly and in stages.

can't help thinking that tape will meet the pilot drill and end up spinning like a rag!

so - grease for the pilot drill with tape underneath - as it goes through remove tape, clean grease and use a little diesel as the cutter gets going.
clean swarf away constantly
finally try and 'cut/ease' disc out rather than cuting all the way with saw.

I don't have a true varialble speed drill that I can use on the boat (no 240v) but I can work with a 24v on the rheostat - it's only thin ally and a new saw.

thanks to all again
 
...and I thought you were a fisherman!

What about using a bandy net covered in a stocking then inserted into tank below the cut to catch any debris?
 
even better to start with a clean dry tank and then hoover out the residue when completed (its what I did. I also filter all fuel going into my tank so that there should not be any of this crud in the bottom of my tank.
 
Can I chip in if I may?
I fitted an Eberspacher a few years ago and took the fuel feed from a spare blanked off port on the fuel filter/water separator I took advice from a local truck Eberspacher installer. Works great, even though this side of the fuel filter is under negative pressure. Was easier for me as access to the tank was difficult.
 
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can't help thinking that tape will meet the pilot drill and end up spinning like a rag!


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Once the pilot drill has broken through and you've started cutting the hole you can remove the pilot drill as the holesaw will now stay in place by itself.
 
now that is a new one to the discussion - thanks David.

I definitely do have a blanking plug in the primary, only had the thing apart for a good clean up last weekend.

Where did you source a fitting from?

The downside as you say is that it's under negative pressure when the engines running and without the benefits of filtered fuel available from a tee the other side of the filter..........which I had already ruled out. If I could source a simple fitting to replace the plug it might be worth trying for it's simplicity.

Always good to have something new bought to the table.
 
Could put a valve in between the filter and the heater unit thats shut when the engine is running. Fittings are available at most plumbing supplies as I found out for my fuel system.

Bit late in the day I know, but if you need a cordless variable speed drill, I heve one or two that will suit the job.
 
clean dry tank certainly sounds a good idea but I think I would have to remove the tank and cut off the whole top to achieve this!
the tank is split into 3 sections f to b by what appear to be full height baffles with presumably a few small holes in them. The fuel pick up is in the rear one, the sender the middle one and I currently have no access to the forward one. Fuel in is also to the middle section; fuel return to the rear near pickup.

Tank removal wouldn't be a job to undertake lightly.......
 
[ QUOTE ]
now that is a new one to the discussion - thanks David.

I definitely do have a blanking plug in the primary, only had the thing apart for a good clean up last weekend.

Where did you source a fitting from?

The downside as you say is that it's under negative pressure when the engines running and without the benefits of filtered fuel available from a tee the other side of the filter..........which I had already ruled out. If I could source a simple fitting to replace the plug it might be worth trying for it's simplicity.

Always good to have something new bought to the table.

[/ QUOTE ]Your filter should have 2 inlets and two outlets with one of each blanked off (single engine installation) If you use the spare INLET tapping the fuel will not be at as high a negative pressure as if you use the spare outlet as you would effectively be drawing fuel off the inlet side as if you had tee'd into the feed between the tank and the filter. The problems can arise when you have high suction on the inlet line between the primary filter and the lift pump (usually due to a clogged primary filter).

Fittings are available from any commercial vehicle factors or from Lucas/CAV.

If you read your installation manual you will find the metering pump can cope with negative pressure, that is it can suck fuel up from a tank located below the level of the heater..
Some installations have a pump at the tank to lift the fuel to the engine, if that is your case then you need a separate tapping on the supply tank or a separate tank.
Where is your main tank located in relation to the engine and heater? (relative height wise)
--------------------
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"Artificial intelligence is no match for natural stupidity"
 
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