Leaking coolant tank

[Philip WoodallParticipant @philipwoodall56656]

just bought a Colchester student lathe and filled the coolant tank to find a few hours later my workshop floor flooded. The tank is integral with the base of the lathe. Difficult to see internally where it's leaking. Doesn't look corroded. Any suggestions as to a repair ? Must be some epoxy treatment to resealable it ? Any suggestions appreciated Regards Phil

[Philip WoodallParticipant @philipwoodall56656]

[David George 1Participant @davidgeorge1]

Hi Philip As a factory service manager I have come across similar problems but mainly on grinding machines but it is usually caused by not cleaning out coolant and swarf for a long time and corrosion makes perforations usually in difficult to get at corners. I would have to clean out and find the holes and then I used an epoxy resin 2 pack but I would coat the whole tank inside making sure that it went through the holes and it would have to be entirely grease free before coating. I used a pack from RS components but not cheap but I never had one leak after and it gives the tank a antitrust coating.

David

[JourneymanParticipant @journeyman]

Depending on the size and access to the coolant tank you may be able to find a suitable plastic container to fit inside it (jerry can, plastic starage box, heating expansion tank, etc) Then just make an access hole in the old tank and re connect the pipework. Might save faffing about in the dark trying to clean out the old tank and coat the inside.

John

[Clive FosterParticipant @clivefoster55965]

Philip

Agree with David that the leak(s) are almost certainly in the corners. Had same problem with my Smart & Brown 1024 tank and did a cheapskate version of Davids epoxy coating repair using the common glass fibre resin as used, for example, in car body repair kits. Chosen mostly because I had large tin in stock due to over purchase for another project some years previously. Some strategically placed glass fibre tissue placed in the corners helped ensure that there was a seal on the vertical sides without needing an inordinate depth of resin. The 1024 tank slides out which made for an easier job, especially cleaning out, but it has internal sub divisions with thin gaps at the bottom to act as pre filters catching some of the swarf before it gets to the pump pick up screen. Keeping suitable filter gaps after the resin repair was bit tricky.

Did the usual tap all over rust investigation and found a couple of larger holes in the middle which needed welded on patches.

Only going too be temporary job until I got a new tank. Getting on for a decade old now. Now't so permanent as a temporary job. Allegedly the synthetic and semi synthetic coolants are better than old fashioned suds when it comes to tank rusting (and paint stripping).

If you decide to try fitting a new tank inside its worth looking at the deep drawn rectangular stainless steel "pans" from catering supply folks. No seams and price is not completely un-reasonable given that its likely to be much more durable than "found" or "re-purposed" tanks. For example GastroNorm (whatever that means) pans come in a range of sizes with depths up to maybe a foot, Google comes up with some decent size diagrams. Probably £20 to £30 for a suitable one. I've got one about 21" x 13" about the place, obtained for some now forgotten reason.

Clive.

Edited By Clive Foster on 12/11/2017 13:45:51

Edited By Clive Foster on 12/11/2017 13:46:38

[richardandtracyParticipant @richardandtracy]

If there is space to do so, a central heating header tank (Wickes 443153) or plastic crate could be dropped in. That should be under a tenner.

Regards

Richard

Edited By richardandtracy on 12/11/2017 14:51:47

[Clive FosterParticipant @clivefoster55965]

Excellent idea Richard. Fold and squidge of a plastic tank seems a much easier way of fitting than twist'n swear as you try to find the right angle to get rigid tank that ought to fit through the hole to actually go through.

If fitting a rigid inner tank its probably a good idea to make an exact size mock up by cutting a suitable near to size cardboard box for trial fitting before purchase. Should have done that last time I had a similar job. Room for tank but not fingers. Had to get very creative with a handling aid to fit firmly inside the tank yet still be extracted after fitting. Far as I can see that one is never coming out. But not my worry.

Need to be sure that the coolant won't eat its way through the plastic over the next few years.

Clive.

[not done it yetParticipant @notdoneityet]

The product Pour-15 is used by many for coating/sealing fuel tanks should be ideal for a duty such as this. Seems like getting a good coating applied might be a challenge.

[Philip WoodallParticipant @philipwoodall56656]

Many thanks to everyone for all the excellent advice. Have spent some time cleaning out the tank with degreaser and wire brush. It's very odd. The internal condition looks good with no evidence of corrosion ?? But there is certainly a bad leak (fast drip). I like the idea of fitting some form of tank liner but the access hatch to the tank void would mean that the only tank I could get in would reduce the tank volume significantly. Have now ordered some epoxy tank sealant . The type used for sealing leaking motor cycle fuel tanks so will give that a go in the first instance.

Very much obliged to all for taking the time to assist. Will post again to hopefully report a successful repair

Phil

[Philip WoodallParticipant @philipwoodall56656]

Well, finally it seems (so far) the coolant leak is cured but was not straight forward. I initially coated the inside with epoxy concentrating on brushing into the corners. Access is awkward. Left is for a few days to cure. Result- leakage was same as before. Frustration !! I then had to go through the cleaning process to get it dried out and clean again. This time I cut some strips of glass matting 2 inches wide and worked these into the corners with epoxy on all 4 sides. Very awkward sticking my head inside to see with a torch trying not to gas myself with the fumes.! Cutting a long story short it now seems to have sealed.

I don't think this is a corrosion issue. The tank is integral with the lathe cabinet so the tank bottom is also the base of the lathe. What may have happened is that someone possibly in moving the lathe may have strained the bottom slightly maybe cracking one of the tank seams.

Thanks again for the assistance

Phil

[Philip WoodallParticipant @philipwoodall56656]

[David George 1Participant @davidgeorge1]

Nice job glad to see you have a working tank a lot of queries don't give a result.

David

[Author]

Posts