Sealant on a roll or Silicone?

Discussion in 'Tech/Mech General' started by zaskar, May 9, 2009.

  1. zaskar

    zaskar Funster

    Sep 25, 2007
    Often wondered on this question.

    I know the manufacturers use sealant (mastic) on a roll a lot, but my thoughts have always been that it was for ease and cheapness (labour wise) of manufacture.
    My personal opinion is that GOOD QUALITY silicone based sealants such as Sikaflex, Dow Corning, or in the case of EPDM, Dicor, does a FAR better job of getting into all the nooks and "crannies" when you're sealing something up........but thats just a personal opinion and not based on fact.
    I also must add that when ever I seal anything up using silicone, I belong to the school of thought which says "its better to put too much on and have to clean up afterwards, than not put enough on and risk a leak".

    Perhaps somebody from the trade might like to comment and give arguments for and against both?

  2. 45eEver


    Apr 15, 2009
    I'm with you on this one Zaskar.

    Tube sealant everytime for refurbishment work.

    However, Sikaflex isn't just one sealant, it's several.

    It isn't silicone, its polyurethane, so it's also an adhesive.
    One of the problems with some Sikaflexs is that when it's stuck, it tends to be well stuck.

    If you contact Sika, they'll tell you the very best sealant for the job you are doing.

    Sikaflexes are not the only sealants that Sika make.

    Try Sika Limited | United Kingdom
  3. mulaz


    Apr 14, 2009
    tube or roll

    I asked the same question as i have just fitted a mini heki.
    i rang the Caravan Clinic Gateshead Caravan for advice.
    and i quote "Members of the National Caravan Council Approved Workshop scheme and recommended by the Caravan Club"
    They advised me to use the mastic on a roll. They even gave me enough for free to do the job.::bigsmile:
    They say that tube based mastic gets squashed out under pressure when tightening up, leaving only a very thin layer, when you think about it's true.
    Anyway i think both have their use's and as they say "HORSES FOR COURSES":thumb:
  4. "Parker" me lady

    "Parker" me lady Deleted User

    Hi all. I bought a nice 2001 Stardream 1.9TD with 1900 miles on the clock, (now 3400 miles),absolutely as new,(cooker, shower/washroom/loo unused!) inside and out, June 2007, I am a little worried about the seals around the front end where it joins the chassis above the windscreen, and also on the top seal across the van's roof about 3 feet back from the roof top front. I spoke to a mate who builds refridgerated delivery vans for a well known co. and he pointed me towards a product by Kommerling, Kora Pur. It's a polyurethane adhesive / sealant, and he swears by it. He said not to remove the original mastic, but, to clean it with white spirit and then apply the new stuff with a nice thick bead, and finish off with a wet, "gloved" finger. As yet I have not done the job, as I need to rig up some sort of trestle to be able to get across the windscreen to the seams easily, and allow a nice smooth finish. The roof is not too difficult a job, but, when it's done later this weekend, I report the results.
    If anyone thinks I am doing the wrong thing, please reply before I start the job, probably tomorrow, Sunday 10th!

  5. Geo

    Geo Trader - Funster

    Jul 29, 2007
    The only comment I would make is on the choice of cleaner,White spirit, or tupentine will leave an oily residue behind and may interfear with the bonding action of the sealer, personaly I would follow up the white spirit with somthing like meths or other alcohol based spirit

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