Die grinder - worth trying shorter hose?

[daleyd]

Asking for the collective wisdom of the forum, as per title...

Ive got a couple of air die grinders, I tried one today to do a bit of cleaning up and noticed when using it the speed is initially good but drops after a few seconds of use.

Ive got a 20m air line (extension reel type) that I’m using it with, I reckon this is almost certainly the cause of the speed (can’t flow enough air so pressure drop through the hose). I’m going to drain comp down tomorrow and have a check to make sure the there’s nothing amiss with the fittings(blocked with ptfe or something). When you release the trigger you can hear a hiss for a few secs after as if it’s filling the hose again - I’ve used the compressor loads for dusting, plasma cutter, inflating etc and it does this whatever you are doing but using the die grinders is the first time I’ve noticed the pressure drop.

So, is it worth getting a short line for use in the garage (5m would see me reach everywhere in the garage.)? If so any recommendations for a decent, but reasonable priced one? A google search seems to bring up loads of reel type ones.

 

[sako243]

I can post a photo of what I've got. No idea what the pipe is - it came with the first second hand compressor I bought and it's beautiful. Reinforced but beautifully flexible, wonder whether it's some variant of hydraulic hose.

 

[grim_d]

What's the bore of your hose? That will make a bigger difference than the length.

 

[Matchless]

can you see the pressure gauge on the compressor, if so does it drop when the grinder slows? sounds like the compressor cannot keep up to me, maybe a couple of calor cylinders as extra air storage might help in the short term, or a tank from a dead compressor,

 

[brightspark]

probably small bore too long coiled up and loosing cfm .try on a short lead or buy a larger bore pipe mine are 10mm bore up to about 8 meters

 

[daleyd]

I can post a photo of what I've got. No idea what the pipe is - it came with the first second hand compressor I bought and it's beautiful. Reinforced but beautifully flexible, wonder whether it's some variant of hydraulic hose.

Cheers - that would be useful.

I think the bore of the hose is 9mm, it’s a metabo reel so a decent make.

The gauge on the compressor doesn’t move - its a 150l tank and the motor is nowhere near kicking in, it happens when it’s at full pressure. I’m reasonably sure it’s a pressure drop issue - i think it’s happened all the time just that what I’ve used it for has not mattered until now - there is a small adaptor between the quick release on the tank outlet and the threaded connection out of the tank - I’ll strip that tomorrow to check.

 

[AndersK]

If you run air consuming tools like grinders put in a large regulator to start with, then use a 1/2" hose and go down to 1/4" the last 1 to 1,5 m for comfort.

 

[brightspark]

I just bought one of these to go on the end of a 15mm bore hose I use https://www.screwfix.com/p/erbauer-...VmpntCh399QolEAQYAyABEgJ_8fD_BwE&gclsrc=aw.ds its half decent I just cut the ends of and fit pcl fittings on with jubilee clips

 

[eddie49]

Here's a s/h 8 meter 1/2" hose:
https://www.ebay.co.uk/itm/Compressed-Air-Hose-1-2-inch/233595739874

with the "Make an Offer" option.

 

[jack-daniels]

I just bought one of these to go on the end of a 15mm bore hose I use https://www.screwfix.com/p/erbauer-...VmpntCh399QolEAQYAyABEgJ_8fD_BwE&gclsrc=aw.ds its half decent I just cut the ends of and fit pcl fittings on with jubilee clips

Why do you cut the ends off?

 

[gordon stephenson]

Top and bottom of the problem is the length of a small bore hose, As already said, larger bore with a short "whip" hose onto the grinder for ease of use and flexibility,

 

[brightspark]

because I already have barb fittings for either end so the threaded fittings aren't needed

 

[jack-daniels]

because I already have barb fittings for either end so the threaded fittings aren't needed

Oh, My OCD wouldn't allow that! Cut a new hose

Would need to be one of these instead.

Plus I find Jubilee clips scratch the paint more when I drop it down the side of the car

 

[anjum]

Cut your existing hose in half or different lengths and use hi-flow euro connectors to connect them and throughout. So you retain the option of short or, when you need it connect the other part or both.
Worth looking at your filter regulator as that may be the problem.

 

[daleyd]

So as an update to this - I got hold of the 10m hose from screwfix that @brightspark linked to above.

It’s like night and day, not what I was expecting given it’s the same bore size (within a mm) as my existing reel that’s giving me issues. Obviously the halving of length makes a big difference, or possibly the fact half was still coiled up on the reel, but whatever I now have no drop in pressure and a full speed die grinder

I have had the reel hose for years and have used it loads but always in factories and never noticed an issue before using air ratchets or impact guns - I may try some more tests at home and unreel the hose completely and try again if I get bored (or need to do some die grinding at the bottom of the garden)

Anyway, I can certainly recommend the screwfix hose as it seems pretty good value and well made - has a lovely rubbery smell too The pcl xf fittings are a decent price from there too (I got a male and female for each end of hose, they match my other xf fittings which I already use).

 

[Kram]

I had the same problem with my sgs compressor, not enough air for a burp gun. What bits should I replace? Might get the hose linked above.
Do I need a higher flow regulator?
www.ebay.co.uk/itm/181321137646

 

[brightspark]

the best bet is put a half inch bsp filter regulator on the end of your tank . no restriction of flow fitted. the machine mart ones aren't so bad and cheap enough for general use I have a decent one on the end of the line as well if im doing spraying

 

[eddie49]

put a half inch bsp filter regulator on the end of your tank

- i.e. replacing the tank end plug/bung.

 

[Kram]

Good idea. Id have to unscrew the fitting each time for storage but only takes seconds. Would it be un safe to have the hose direct to the tank and regulator on the end, incase the hose gets damaged?

Am I better off making my own hose with 1/2" bore and bsp fittings or is the 10mm bore adequate?

 

[Kayos]

Pressure loss in a pipe is proportional to length and pressure but increases exponentially with length.

See, I did listen at college