peterm Posted October 19, 2016 Report Share Posted October 19, 2016 A spare radiator which I have is blocked with a considerable amount of sludge. Externally it is in good condition, but no matter how much I flush it the flow is still poor. The radiator is not fitted at the moment. Any suggestions as to what solution or products whether automotive/domestic I could use as a soaking agent to loosen the crud. Cheers, Peter Quote Link to post Share on other sites
Don H. Posted October 19, 2016 Report Share Posted October 19, 2016 http://www.evapo-rust.com/thermocure/ I've been very happy with this company's other rust-removal products and I'm going to use this cooling system cleaner when I change coolant before the Spring. Here's what regular EvapoRust did with the hose clamps from my car's original heater: Quote Link to post Share on other sites
ctc77965o Posted October 20, 2016 Report Share Posted October 20, 2016 (edited) Hi Peter, I have cleaned rads successfully with coke before. I get a large pan of water on a stove, lay the radiator on top, fill radiator with cheap cola then bring water to boil to steam the whole thing...do it more than once if.the rad is really cruddy. Afterwards inside will sparkle like New... If it's really blocked then I would ask an old school radiator shop to 'rod' it...meaning desolder the header and then mechanically clear all the tubes. Then resolder the top and do.the coke treatment Edited October 20, 2016 by ctc77965o Quote Link to post Share on other sites
john.r.davies Posted October 20, 2016 Report Share Posted October 20, 2016 Unlike the whole surface of a hose clip, or the inside of the top tank of a radiator, crud in the tubes shows a tiny area in relation to the size of the blockage. It will take a very long time to dissolve the crud! But as the rad is off the car, why not let it soak in something, for weeks if necessary. The other problem is that rad cleaners are designed to work in a hot engine. Chemical reactions go much faster when hot. Some way of heating your rad from time to time or keeping it hot might help. But I wouldn't hope for much improvement. Better as suggested to get the rad rebuilt. Not "rodding" the tubes (what that?) but a complete new matrix, perhaps deeper with more tubes than OE. Cheaper than a new rad, still not cheap, but a definative, reliable solution. John Quote Link to post Share on other sites
John Morrison Posted October 20, 2016 Report Share Posted October 20, 2016 The the inexpensive, 'At home' way of doing this is with Caustic Soda - drain cleaner. BUT YOU NEED TO TAKE CARE. Wear heavy gloves and good eye and clothes protection, and follow the instructions on the pack, especially be sure to add the caustic to water and NOT the other way round. get the rad hot, - kettle of boiling water or a steamer, add half a cup of Caustic to half a watering can full of warm water - carefully, add to rad and agitate vigourously, you can close off the outlets with redundant top and bottom hoses closed off with anything that fits, and the rad cap. Agitate leave and repeat if necessary. John. Quote Link to post Share on other sites
RobH Posted October 20, 2016 Report Share Posted October 20, 2016 "The inexpensive, 'At home' way of doing this is with Caustic Soda - drain cleaner." OK for a brass rad but never use that near an aluminium one - caustic soda dissolves aluminium. Quote Link to post Share on other sites
Lebro Posted October 20, 2016 Report Share Posted October 20, 2016 If it's really blocked then I would ask an old school radiator shop to 'rod' it...meaning desolder the header and then mechanically clear all the tubes. Then resolder the top and do.the coke treatment +1 Bob. Quote Link to post Share on other sites
mike ellis Posted October 20, 2016 Report Share Posted October 20, 2016 Hi Pete, If the crud is limescale I would be inclined to use citric acid to dissolve it, it's a weak acid so the effect on any copper would be minimal. It is a recognised descaler for many applications. Mike Quote Link to post Share on other sites
monty Posted October 20, 2016 Report Share Posted October 20, 2016 Peter, I am not too sure why you are going to all this trouble with what sounds like a finished rad. Why not try to part exchange for a nice new one from the likes of TRGB? I got mine a few years ago, just sent off the old leaking one & received a reasonable priced reconditioned item in return. Quote Link to post Share on other sites
ctc77965o Posted October 20, 2016 Report Share Posted October 20, 2016 http://www.cgj.com/2013/08/15/how-to-clean-a-radiator/ Quote Link to post Share on other sites
ChrisR-4A Posted October 20, 2016 Report Share Posted October 20, 2016 I used Fernox to clean my rad, as used by plumbers in central heating systems. Had all sorts of warnings on tin, gloves, goggles hard shoes, keep away from everything etc. It did remove a little more crud from the rad but made no difference at all to cooling in the car. Complete waste of money and time. Ended up having rad rebuilt with larger more efficient core, best £240 ever spent, no problems at all now. Chris Quote Link to post Share on other sites
MikeF Posted October 20, 2016 Report Share Posted October 20, 2016 Hi Peter, I have cleaned rads successfully with coke before. I get a large pan of water on a stove, lay the radiator on top, fill radiator with cheap cola then bring water to boil to steam the whole thing...do it more than once if.the rad is really cruddy. Coke contains a small amount of phosphoric acid as the active ingredient in this application. Possibly the fizz will give a bit of scrubbing action, Were I using coke though I would shake the fizz out and add a little low foam detergent (like Flash Floor cleaner) to help float the crud out. Having said that I wouldn't use coke, but a proprietary cleaner. There are specialist car radiator cleaner products, or plumbing products. Unlike Chris above I found Fernox effective, but you do need to back flush to lift the crud. Mike Quote Link to post Share on other sites
Lebro Posted October 21, 2016 Report Share Posted October 21, 2016 get it re-cored. Bob. Quote Link to post Share on other sites
littlejim Posted October 21, 2016 Report Share Posted October 21, 2016 I'm with Lebro - you want it to be spot on. Shame to cook the engine because it was 'nearly' cleaned. Quote Link to post Share on other sites
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