Rust stains on renders can be caused by flue pipes, satellite dishes, mild steel fixings, overflow pipes, etc. And they can cause an otherwise sound property to look unsightly.
* Our tests showed positive results on all the renders we’ve tried it on except cement based render. (i.e. sand and and cement, which should be painted anyway – and in which case it too will be fine).
In the picture below you can see rust stains caused by fittings on a flue.
We brushed Oxy Cleanze on and left it to work. Temperature was 15 ℃
Notice the difference in the photo below after only 3 hours (it would have been much quicker in warmer conditions).
You can see that, although dramatically improved, there are still some faint marks, which will likely become less pronounced over time. You can see the shadow left behind as a result of the treatment, which is a side effect on some renders. A repeat application of our rust remover gel could be beneficial.
Quick tip: The key to successfully removing rust stains from renders is to apply Oxy Cleanze rust removal gel only to the specific areas that need treating. On some renders and masonry there may be an undesirable bleaching effect. Always treat a small, inconspicuous test patch, and get your customer's agreement to treat the whole area, before completing the contract.
In the photo below you can see the stains caused by rust from a hanging basket bracket.
We treated the rust with Oxy Cleanze rust remover gel and and successfully removed the staining.
However, notice the shadow left behind, which is the side effect of over-using Oxy Cleanze on this type of render. This photo shows the importance of applying rust remover gel only to the areas that need treating.
The photo below shows a similar bracket where we used a smaller quantity of Oxy Cleanze and the results, as you can see, were much improved.
We hope this information is helpful.
Ben, Leo & Fiona