Firstly, I am sorry to hear you are having this problem. Builder’s Bog is made in a batch process with 1000 to 2000 litres in a mix. Each batch is then tested and adjusted for gel time at 22 Deg C in a water bath using 40 grams of product and 1 gram of red hardener. Gel times controlled to 6 to 7 minutes by adding various accelerators or decelerators as required. That is enough history, but this does make it hard to explain your problem.

Relative to shelf life, as the product ages (up to 5 years or more in our tests) the gel time gets shorter and shorter until the material in the can is finally too stiff to use. Eventually it becomes a solid. This is the opposite to the problem you are having. If you add too much hardener (i.e. beyond the limit we specify on the can) the product will not cure, and neither will it with insufficient hardener again beyond the lower limit we specify).

This may or may not help you, and I fully realise that no-one wants to hear that they did not follow the instructions to the letter. But in a complicated product where very specific chemical reactions are involved, the ratios are very important. So I suggest that you try out a portion using an old spoon for the hardener (a level teaspoon should hold 5 ml. if of “normal” size). This is 6 grams.

Then estimate, or -better – weigh out 240 grams of the paste and mix with the hardener. This will gel in about 8 minutes or less at 20 deg C, depending on how old the sample is. It cannot be more, because we set the Gel time of every batch after manufacture and it never varies except by ageing. I hope this helps. Please email me to let me know your results, since customer responses are very important to us.

Regards
Stuart Jordan
Managing Director, Chemical Specialties Ltd.
17.7.2013

I have gone and tried your suggested mix rate and yes it works and works well but I now see what went wrong. I am a tradesman aged 63 but really only working as a handy man in the last 8 years. I had never used builders bog before (I previously used spakfiller type products and long time ago plastibond). So I bought a 2 litre container at my local small hardware shop. Yesterday very carefully read the instructions and very carefully got the quantities correct(worked with scientists for 30 years).

BUT today I poured out the hardener with my reading glasses on and thought gee this is really very liquid like when I did it yesterday but then as I looked at the hardener container closely I noticed that the hardener has completely separated into two substances – one half longitudinally along the whole container a very hard paste and the rest a very liquid liquid. I have reread the instructions on the tin and nowhere does it say reconstitute an evenly thicksatropic(see even if I can’t spell I did work in science) substance within the hardener container before use. I did this and it worked.

Clearly sitting on its side on top of the tin in the plastic top over along period in a non air-conditioned hardware shop the hardener separates and if you have never used it before and don’t look closely(at arms length it looks full of red stuff) you seek and get a red hardener out – nothing says anything about the possibility of separation. Not very happy but concede that had I looked closer I would have noticed – guess my plastibond experience yonks ago had me thinking liquid red stuff = ok. The next question is the job I did yesterday using the correct amounts but only liquid form hardener ever going to harden? The client is away for 10 days. If I could offer constructive advice then you need to cover the possibility of separation in your instructions.

Hope this helps.
Doug
(17.7.2013)

Thank you very much for replying, which is most helpful to us. I had not even considered the hardener may have seperated. This normally takes many years unless stored at high temperatures. The red paste contains 18% water dispersed with a detergent in the “oil” phase. The oil phase contains the benzoyl peroxide hardener as a fine powder and an ‘oily” vehicle to make it into ma paste. The water is in there to make the product stable, as otherwise it can decompose suddenly as the temperature is raised.

I will immediately review our procedures and check old hardener sample at our factory (we keep samples of all components for 5 years minimum to observe shelf life. Incidentally, many years ago Plastibond was my brand in NZ. I sold the rights to Selleys in the late 70’s. At that time it used an MEKP liquid hardener, so no wonder this red stuff confused you!. I do apologise and suggest it would be good to return the hardener and change it for newer stuff. You can show them this email if you wish. I formulated Builder’s Bog many years ago (I am 69) and many older products before that.

I am afraid that the job you did with the white separated liquid will never cure and needs to be scraped out. Also, please be very sure all rot spores are removed or neutralised from surrounding timbers, since I have seen many cases where the Builder’s Bog repair is the only bit remaining – the timber around it having continued to rot.

Regards
Stuart Jordan
Managing Director, Chemical Specialties Ltd.
18.7.2013