Cleaning mastic sealant

dougA
dougA Forum Participant Posts: 142
edited January 2018 in Caravan & Motorhome Chat #1

Washed my motorhome today and noticed that the white mastic sealant is looking dirty in some places.

Any recommendations on what's the best cleaner for this job?

Comments

  • AJB
    AJB Forum Participant Posts: 120
    edited January 2018 #2

    If the mastic is of the 'semi solid' or 'solid' type I would try Silky - in a not-so-noticeable place.  To apply in areas such as around the awning rail, or in narrow gap, I would use an old toothbrush.

    BUT BE GENTLE - the sealant is there for a reason....

  • dougA
    dougA Forum Participant Posts: 142
    edited January 2018 #3

    Hi AJB for the quick reply. Just been out to check the sealant and it feels rubbery/flexible not solid. 👍

     

  • Tammygirl
    Tammygirl Club Member Posts: 7,957 ✭✭✭
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    edited January 2018 #4

    I would agree also SILKY, its what we use for the mastic on our MH, as AJB says toothbrush or a soft cloth, cleans off all the black bits and the green algae.

  • AJB
    AJB Forum Participant Posts: 120
    edited January 2018 #5

    Rubbery/flexible is good....where I would not use is the tacky bedding sealant.  Try somewhere unobtrusive, even if not too dirty - what you are testing for is for the sealant not to be dissolved or disturbed. I hope that makes sense.  One final word - just be mindful how much you will need to do if you get the test result you want!! 

  • lornalou1
    lornalou1 Forum Participant Posts: 2,169
    1000 Comments
    edited January 2018 #6

    have you tried any of the cream cleaners like Cif and a soft damp cloth.

  • JohnM20
    JohnM20 Forum Participant Posts: 1,416
    1000 Comments
    edited January 2018 #7

    To be effective for a long time the mastic has to remain soft and sticky. This means that any visible edge will pick up any airborne dirt until the whole of the exposed edge is coated. Cleaning it off will only allow new dirt to reapply itself to the edge.  I think the only way to stop a dirty visible line would be to deliberately apply some 'dirt' in the form of something white that would match the caravan / motorhome and that would effectively 'kill' the exposed adhesive. What that could be I'm not sure but it would need to be something inert that itself would not absorb or hold airborne or rain-borne dirt. Very fine silver sand may be a possibility. Personally I've just learnt to live with the dirty lines which will be found on just about every other caravan / motorhome.

  • dougA
    dougA Forum Participant Posts: 142
    edited January 2018 #8

    Hi, not tried any sort of cleaner yet other than car wash cleaner. I was not sure about household cleaners as they may have chemicals that would react to the sealant or paintwork.

    Yes I understand that it will be almost impossible to keep it clean all the time but I'm just wanting to make it look as best as I can after washing.

    ive ordered some of the silky cleaner to see how it goes.

    Thanks again all, I new I would get some great advice as usual 😀👍

  • cyberyacht
    cyberyacht Forum Participant Posts: 10,218
    1000 Comments
    edited January 2018 #9

    Don't stand so close then you won't be able to see the lines. wink

  • lornalou1
    lornalou1 Forum Participant Posts: 2,169
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    edited January 2018 #10

    i do like your dry sense off humour cyberyacht.

  • Tigi
    Tigi Forum Participant Posts: 1,038
    500 Comments
    edited January 2018 #11

    Clean with a strong solution of Fenwicks using a toothbrush, once clean and dry and apply a car polish over the mastic to reduce the speed at which dirt will reattach, once the mastic becomes internally stained with black mould there is`nt much you can do.

  • dougA
    dougA Forum Participant Posts: 142
    edited January 2018 #12

    Silky delivered today and tried a small area and excellent results. As mentioned I used the silky on a toothbrush and it cleaned off the crap and back to clean white 😀.

    Thanks AJB & all for your replies/tips 👍

  • EmilysDad
    EmilysDad Forum Participant Posts: 8,973
    1000 Comments
    edited January 2018 #13

    I'd question whether even a toothbrush was soft enough to not scrape/damage the sealant. I just use a sponge. laughing

  • dougA
    dougA Forum Participant Posts: 142
    edited January 2018 #14

    Hi MollysMummy, the toothbrush was a old soft bristle one but I’ll try the sponge as I only tried a small area to see how it cleaned 👍.

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