Which sealant (again!) for toilet door?

Sep 23, 2013
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There are now so many sealants/adhesives around from a variety of different manufacturers that I am thoroughly confused. :(

I am about to fit a new Thetford Access Door type 3 - otherwise known as the door that lets you remove the toilet cassette from outside of the van. There was an argument with a sticky-out bit on a gatepost that wasn't visible in the dark while doing a complex vehicle reshuffle on a mate's driveway. :(

The instructions just say fill the groove in the door frame with sealant, without specifying what sort to use. It is purely a sealant function required - the door is screwed in place, so no adhesive property required.

It's to go in a steel panel van side.

Any specific recommendations? On the face of it, I would guess that almost any sealant rated for outdoor use would do, but very happy to be guided in the right direction.

It's a black door in a dark red surround, so there is some sense in looking for a black or at least dark coloured sealant, but if done with care, I don't think it will be very visible anyway.

Grateful for any suggestions. Also for any fitting tips or things to watch out for from anyone who has fitted these doors before as a replacement. (y)

I have Screwfix, Halfords, B&Q & a builders merchant local to me.
 

TheBig1

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you need a non setting bedding mastic, virtually any type with a high melt point. I prefer to use w4 mastic on a roll but it is light coloured. Personally i would pick a black frame sealant mastic from screwfix

replacing the door and frame really is straight forward, just need to use white spirit to clean off the residue of the original mastic
 

Terry

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Puraflex 40 sealents and adhsive or Stickall (y)both in black ;)

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Jul 29, 2013
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I like Stixall as you can even use it on wet surfaces and it’s a good strong flexible sealant
 

PP Bear

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This is pretty good stuff....
https://marinestore.co.uk/Sikaflex_512_Caravan_Sealant_300ml.html
IMG_4392.JPG
 

funflair

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I would be guided by what the manufacturer used, if its non setting mastic I would go with that, if its a setting sealant go for that. Would lean towards non setting though.

Martin
 

Terry

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I would be guided by what the manufacturer used, if its non setting mastic I would go with that, if its a setting sealant go for that. Would lean towards non setting though.

Martin
The only problem with that Martin is maufactuers tend to use stuff that is clean to use rather than what does the job best ....sounds daft but they do....I used to know a guy who worked for Bostik and he told me just that ....experience tells me to believe what he said .... I also know a few lads who work for manufacturers and they say the same , does not seal as good but clean to work with
Terry
 
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TheCaller
Sep 23, 2013
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Thanks all for your input. Really helpful. (y)

So - a flexible frame sealant that is not an adhesive. I've looked at the Screwfix website, just because we have a depot up the road. That leads me to this product as looking the best available from their range.

Nemesis Mighty Frame & Glazing Sealant Black 290ml

Agreed?

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Gromett

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If it has screws then a sealant, I would also recommend a non setting mastic tape. (I used this on my windows)
If it has no screws then you need a glue, in which case sikaflex would be my personal choice. (I used this for solar panels etc.)

I personally don't mess around with the alternatives as I don't want to risk it.
 
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TheCaller
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If it has screws then a sealant, I would also recommend a non setting mastic tape.
As per my opening post, the door is screwed in place, so this is purely a sealant. If I have another argument with the gate, I might need to take this one off again :( although I do know where the sticky-out bit of my mate's gate is now, so will be more careful in future! So I do not want an adhesive.

Tape sounds ideal, but there is a 10mm x 1mm groove to be filled with sealant, so the tape would need to be the correct dimensions, although I don't suppose it needs to be exact. The groove also follows the rounded door corners, which might be harder to do with tape.

I've never used tape myself (I only have to do these sort of jobs about once in ten years :D2) so I don't know how it performs in these circumstances. Squirty sealant is more of a known quantity (if potentially more messy!).

At the end of the job, I should have most of a tube of sealant left over, so if anyone needs a small amount of black sealant in the next month or so & is either in Lincolnshire or we are at a handy meet, shout up.
 

Gromett

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Tape sounds ideal, but there is a 10mm x 1mm groove to be filled with sealant, so the tape would need to be the correct dimensions, although I don't suppose it needs to be exact. The groove also follows the rounded door corners, which might be harder to do with tape.
It is not really a tape as such, it is non setting mastic which is bit like a putty covered in plastic on both sides. You peel one side off to apply it. Then remove the top sheet of plastic.
Because it is putty like it goes round the bends easily enough. Then you put the item you are attaching on and screw it down, it squeezes any excess out and you can cut it with a blunt knife (careful not to damage the wall).. Then I used a putty blade to smooth the edges to make it neat.

I wasn't keen on the idea when I was told to use it, but it has been fantastic. I fitted a seitz window which is designed for a flat sided wall on a caravan to my curved wall panel van. At the top and bottom I doubled up on it and the middle only a single layer. It hasn't leaked, and still looks like it did when I installed it. Much easier to clean up after than tube based sealant.

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TheCaller
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It is not really a tape as such, it is non setting mastic which is bit like a putty covered in plastic on both sides. You peel one side off to apply it. Then remove the top sheet of plastic.
That sounds good. Do you have a product name or a link? The only stuff I can find that sounds like that are adhesives as well as sealants, which is not what I want.
 

Gromett

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That sounds good. Do you have a product name or a link? The only stuff I can find that sounds like that are adhesives as well as sealants, which is not what I want.
It was years ago sorry so I don't know the specific one I ordered.. But it was something like this.
http://amzn.to/2ANbayn

You will want to find one that roughly matches the size you need.
 

TheBig1

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the recommended tape mastic is distributed by w4 and can be found in caravan accessory shops and of course ebay

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OP
TheCaller
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Thanks chaps. The W4 sounds great for general use, but:-
It's only in white or grey. I could probably get away with the grey, but this is a black door on a dark red surround.
The narrowest available is 19mm. I would have to split it lengthwise as I'm filling a 10mm groove. Possible though.
It is 2.5mm thick. I am filling a 1mm deep groove. That means a lot of mastic to be squeezed out the side & be cleaned up afterwards.

I've just been out for another look at the van, because I wanted to confirm that the door fitted flush with the steel van side rather than standing slightly proud on a bed of mastic. Actually it does neither. Globecar fit a rubber gasket between the door & the panel. I think this is because there is a very slight curve on the panel.

I know that if the door sat flush, there would only be a 1mm thickness of sealant (so a lot to squeeze out if I used mastic tape). What I won't know until I remove the old door frame is whether there is a rebate in the rubber gasket to accept any sealant. The van lives out on the street opposite the house, so I can't take the old door frame off until I'm ready to put the new one on, so I'm having to guess at how thick the sealant will need to be. Note that there is no visible sealant showing extruded from the sides at the moment. I may even find that the rubber gasket negates the need for any sealant at all.

That takes me back to the idea of sealant in a gun, because that gives me the greatest flexibility to react to whatever I find once I start dismantling the old door.

I can cycle up the Screwfix & get a tube of black sealant for £5.59. I'd have to order tape, which would cost twice as much, plus p&p. If it turns out to be the wrong decision once I start, I'll put it together temporarily with no sealant, duck tape round it to stop the rain getting in & send off for something else. The old door is held on with duct tape at the moment, so it won't look any worse for a day or so. :D
 
OP
TheCaller
Sep 23, 2013
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Well that didn't go as planned. :(

There are 9 screws holding the door frame in place. As it's only about a foot square, you would think that was adequate. But apparently not, because Globecar have glued it in place. They've used good stuff too - I am at a loss to know how to remove it, or at least how to remove it without damaging the surrounding paintwork.

In reality, I suspect the screws are only there to fill in the screw holes. I think it's the adhesive that is the real fixative. Having had a feel around behind the panel, some of the screws only appear to go into the insulation, rather than anything more substantial. They don't appear to have much of a hold on the steel side panel of the van & there isn't anything very solid inside it, such as wooden framing.

The main damage to the original door was to the rubber seal between the door & the frame & both the hinge pins were broken. There is a crack in the plastic door outer which isn't too severe & a short piece broken off the long middle section of one of the hinges on the frame. So for now, I've swapped the seal from the new door & used the new hinge pins & fixed the old door back on. At least it's no longer held on with duct tape & I can empty the cassette!
 

TheBig1

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The only way to remove a door frame bonded on with sikaflex is to cut through the glue with a serrated cheese wire. They are sold for removing bonded windscreens on cars. Under £10 on eBay last time I checked.

Put the wire between the panel and frame and work your way round with a sawing motion. Then carefully clean off the residue on the van before installing the new frame

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