How to open a plastic hatch?

[Phototropic]

I have a whale 5 manual bilge pump on board and I can't for the life of me open the inspection hatch on the back. I would like to service the unit. Have tried by hand obviously and also tried a strap wrench but the wrench wont really grip due to the thumb grips on the hatch on the back...any tips or tricks for stuck hatches appreciated ?

 

[alahol2]

I sometimes have to persuade mine with a block of wood and a hammer. Just do it carefully and at several points round the circumference.

 

[mtb]

pour boiling water over it

 

[septiclecky]

Is this what you have?

http://www.whalepumps.com/marine/si...library/ExplodedView/MBP_MK5_DoubleAction.pdf

http://www.whalepumps.com/marine/si...mK_5_Double_acting_pump_instruction_sheet.pdf

 

[Spirit of Glenans]

Seems to me a bilge pump which cannot be instantly opened up for unblocking is a serious liability.

 

[[3889]]

How big is it? Any chance of it fitting in the gape of a large stilson?

 

[duncanmack]

Gland/water pump pliers

http://www.ebay.co.uk/itm/AM-TECH-16-400mm-GROOVE-JOINT-PLIER-WATER-PUMP-PLIERS-/400701437379

 

[colind3782]

Chain wrench?

 

[prv]

Flat screwdriver against one of the thumb grips and tap round with a hammer. Or use something softer if you don't want to mark the plastic, but it will probably be a bit more fiddly to hold in position.

Pete

 

[alahol2]

Each time I have to tap mine around I think I must make a 'key' for it. All it needs is a batten with a chunk as long as the diameter of the lid cut out of the side.

 

[davidpbo]

Maybe put some silicone grease on the thread when it is off. I would use hot rather than boiling water.

 

[Phototropic]

@septic - yes that is what i have...

Mmmm well i tried hot/boiling water and tapping with a mallet, a mallet and screwdriver and a mallet and wooden block but still no luck??

Will definately put silicone grease in if i ever do get it open....

 

[catlotion]

I have exactly the same problem. Keep trying it from time to time but it just won't budge. Hope you find a way! Might try a chain wrench if I remember to take one.

 

[Phototropic]

Chain wrench?

Is there any reason a chain wrench would work better than a strap wrench? the issue is the thumb tabs on the cover dont give a smooth surface for friction...

 

[septiclecky]

Have you tried a C spanner?