Discussion in 'DIY' started by Fablonbiffchit, Apr 12, 2010.

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  1. Just under the beading that goes around the bath the sealant has started to peel away. I only reapplied it November (not a cheap sealant). I followed the idiots guide and ensures all old sealant was removed, the area clear and any and all other to dos. I ensured the bath was full once the sealant was applied. Its making the bath look a right state.Any tips greatly appreciated.
  2. Can you post up a picture so I can see what you mean properly. Im assuming that you are talking about the beading on floor which is pushed up against a panel of some sort.

    If the sealant is coming away again, this could be because everytime you fill the bath and get in, you are putting pressure on the bath panel which in turn could be pressing against the beading, forcing any sealant to move and come away.
  3. If the sealant is coming away again, this could be because everytime you fill the bath and get in, you are putting pressure on the bath panel which in turn could be pressing against the beading, forcing any sealant to move and come away.[/quote]

    Its the sealant on the top of the bath. I only use it to stand in as I use the shower but my better half uses the bath and she's only 7 stone. The bath is level.Its only in a small area. Would I need to rempove the beading and reattach it?
  4. Bin the silicone and use Teleseal. Lasts for ever and never leaks.
  5. Any tips for the sealant to be used (and techniques) around sinks & worksurface edges? Mine looks a bit grotty and being a DIY biff I've been putting it off for fear of it looking like it was applied with Albert Steptoe's teeth.
  6. Hi,
    clean away all the old silicon , the more time you spend claening all the old stuff away the better it will look.
    Ok once cleaned up and dry run 2 lengths of masking tape leaving about an 6-8mm gap from the corner of where worksurface/ tiles meet ( hope that makes sense.
    Right with your silicon cut the nozzle at 45 degrees and with about a 4-5mm hole ie the further back you cute the bigger the hole gets.
    Ok in one slow and easy motion start applying the silicon where it needs to go. dont put too much on , you can always put more on later. Right here comes the good bit wet you finger and rub it along the silicon smoothing it into the corner. If you are happy then peel off the masking tape while the silicon is still wet. Stand back and admire and say job jobbed!

    Kind regards

  7. You don't do this for a living, do you? :)

    Silicone sealant needs room to stretch but it's rare that the people who put the bath in allow for this absolute requirement. Pull your bath 8mm away from the wall. Clean the wall and edge of the bath with a degreaser such as acetone soaked into a cloth. In lieu of the proprietary back-up rod (think miniature pipe lagging), get some 10mm polypropylene rope and wedge it into the joint, pushing it down 6mm below the top edge of the bath. Apply the sealant as normal, leaving a fillet finish to assist water run-off. To smooth it off, don't spit on your finger and wipe along the sealant - you'll encourage mould. Instead cut a piece of wood to a handy shape and soak it in water for at least 30 minutes beforehand, keep wiping it and wetting it as you tool the mastic into shape. Don't use soapy water for this as many "professionals" do, the soap will prevent the mastic sticking to the surfaces.

    The masking tape mentioned in RM's post is a very good idea, though, and should leave you with a smashing finish.

  8. You don't do this for a living, do you?

    I spent about 6 months labouring for a shop fitting firm whilst in between jobs , tis amazing what you pick up! When it comes to shop-fitting everything and i mean everything needs to be spot on or it looks shoddy.

    Kind regards,

  9. RM, I'm not having a go at you, but I've had 20+ years in QA/QC (among other things) and of the thousands of people I've seen applying mastic, there's only been about two who have actually done it according to the manufacturer's instructions. Almost all have bad habits and pass them on to their juniors who believe that what they've been told is gospel. As you say, a good finish is important (after all, it releases the payment), but few are actually called back to rectify their own work when it goes wrong a year or so down the line.
  10. Hi Puttees,
    Didnt think you were having a go for a second! Just saw someone doing that way once and thought my my he made it look easy!!

    kind regards,

  11. Go to e-bay and buy a 'fugi kit' Cramer make the best ones - and no I had never heard of one 'til my builder bro in law showed me his when he refitted my kitchen last year (even Topps Tiles looked blank)

    They are sets of 3 or 5 little silicone tools to help you easily to get an even and secure seal when you apply sealant.

    About £15.00 last time I looked - worth every penny
  12. Back to the bath scenario...

    It comes down to maths. If you want to seal between two items (in this case the bath and the wall) which have some relative movement (the bath moves as you fill it with water), you need to provide a joint at least twice that of the movement. With a bath, you can cheat a bit by half filling the bath when you install the sealant so you only have to allow for half of the movement.

    If the bath edge is going to move, say, 6mm, then you need a 12mm joint. Half filling the bath reduces this to a 6mm joint (the bath will be moving up and down 3mm, rather than just down 6mm). The sealant needs at least a 6mm bond length, so the joint needs to be at least 6mm deep. Add in the requirement that the width/depth ratio should be between 0.8 and 1.2 and you'll see that there's a maximum sealant thickness to consider as well. If the joint is 8mm wide, the maximum joint depth is about 10mm.

    For it to work at all, the sealant should only stick on opposite sides of the joint. If it sticks at the bottom of the joint, there'll be too much stress on the sealant and it will rip itself apart over time. That's why I mentioned the polypropylene rope in the earlier post - it provides the correct depth of sealant and the mastic won't stick to it.

    So, next time that anyone gunges mastic into a joint, consider that you need to be working to millimetre accuracy if you want the sealant to last.
  13. That's a good idea, though I'd still be inclined to use the masking tape.

    Something else to remember is that mastic skins quickly. Tooling should be complete within 5 minutes of the start of application otherwise you won't get a smooth finish. It's not a long time, so a handy tool like this will reap benefits.

    Bathrooms are generally warm and humid places, causing the mastic to skin quicker. DIY mastic work is therefore best done in the winter to give yourself a bit more time.
  14. Take saucer of Washing-Up liquid to your seal. Put some on your Finger, Cloth, Tool and it will clear a clean flat surface on your seal, when finished, if you move fast enough.
  15. Don't.

    The main pupose of tooling isn't just to give a nice finish, it's to push the sealant hard against the surface to be sealed. If the washing up liquid gets on that surface before the sealant, it won't stick. If it doesn't stick, you may as well not have the sealant.

    Besides, you'll discolour the sealant. Green Fairy liquid gives you a pastel green seal instead of a white one. That grapefruit stuff turns it pink.

    Use a finger and you'll end up with a fingerprint at the end. Use a cloth and you'll just have a mess.