Exterior sealant

[TerryIvybridge]

I'm very proud of our new Abbey GTS, its very clean inside and out,but, around the outside locker doors wher fittings meet body panels, the sealant makes it look shabby. I would like to gently cut back the old stuff and re-apply a new bead of sealant. Whats the best one to use for this, as I'm sure others have felt the same .

 

[Damian]

Dont go cutting away at the sealant, once you start it will weaken the bond.
Also trying to apply a secondary sealer to existing sealer will not work, new will not stick to old and will look even worse than the present situation.

 

[TerryIvybridge]

Wow Damien! thats a pretty damning statement. Surely there is a way to either clean up or replace the gungy joints. I was thinking that there would be a special tool to run round the joint without going right into the corner, and applying a fine bead aound directly after, quadrant style without wet fingering.

 

[Damian]

The only long term successful way is to totally remove all the old sealant, which means removing the fittings , cleaning up the fittings and van ready for re sealing and then re sealing with the correct caravan sealant.
However, you must do whatever you think. After all, its not my van and not one I am being paid to work on,.

 

[Parksy]

Wow Damien! thats a pretty damning statement. Surely there is a way to either clean up or replace the gungy joints. I was thinking that there would be a special tool to run round the joint without going right into the corner, and applying a fine bead aound directly after, quadrant style without wet fingering.

It's a fair bet that I may have found a 'prettier' way to put it Terry (assuming that I had sufficient knowledge) but the bottom line has to be that you have been given totally honest advice from an approved and fully certified professional caravan engineer.
If you feel like tidying up the sealant it's your caravan, but I have to be honest and say that if a fully certified caravan engineer advised me to either leave well enough alone or do a proper full scale job I'd be inclined to take notice even though the message may seem a bit blunt and probaly not really what I wanted to hear.

 

[colin-yorkshire1]

hi Terry,
sorry mate but Damian and parksy are spot on, once you do anything with the sealer it will not seal properly only way is to replace it, and if your van is water tight why bother it can only lead to problems later on.
I have found though that while cleaning the van a soft sponge a mild detergent will clean it up a bit, but it won't remove all the dirt as the sealer is soft and non setting and the reason is gets black.

 

[TerryIvybridge]

Ok, I'll bow to superior knowledge, totally understand the advices. Guess I'll just have to get the toothbrush out and give all a gentle scrubbing, see if that will help.Perhaps I overstated the appearence a little, but black lines around an otherwise shiny clean 'van is a shame..........thats all.

 

[TonyG]

I use a tooth brush dipped in white sprit, then imediatley wash off with soapy water

 

[JohnM20]

I agree totally with Terry and no doubt many others about the messy appearance caused by dirt sticking to sealant and, whilst bowing to Damian's technical caravan knowledge and expertise, I can't fully understand his warnings. Perhaps he would explain further.
This is how I see it. The seal being created with the mastic is intended to be effective between the two components, that is the caravan main body panel and, for example, a locker door surround. Any sealant that is protruding beyond the surround cannot be improving any seal. If it was then the manufacturer would ensure that the sealant protruded beyond the frame all the way around and not just in odd places which is what I have experienced. I'm fairly certain that it isn't the caravan manufacturers intention to have some sealant oozing out in odd places, it is just that where an excess is applied it has nowhere to go but beyond the edge of the component it is sealing. Time / cost then prevents the surplus from being removed during manufacture. It could also be queried that if it isn't oozing out all the way around the component was enough put on in the first place ? The caravan manufacturer's answer would almost certainly be 'yes, of course there was' . And they are probably correct. (On my own caravan there are places where it is impossible to see the sealant but a couuple of inches further along it is oozing out and I've suffered no water ingress).
Why, therefore, is the removal of very small amounts of surplus adhesive, which is totally water impervious in itself, likely to cause a breakdown in the seal ? On the face of it it doesn't sound logical.

 

[Dustydog]

Looking at Sikaflex 512 caravan sealant it is described as:-

Multi purpose non sag elastic one part sealant.
It is resistant to UV radiation, ageing and weathering.
Back in the annals of time I seem to recall that during the "curing" process the outer layer of sealant forms a protective skin whilist that within the joint remains flexible. Once the chemical during process is complete that's it. So fiddling with the outer layer as proposed will only result in tears. The exposed innner layer will not "cuere" as original. In effect the efficacy of the joint has been destroyed.

IMO everything Damian and Parksy have said is correct. So you have the two options.
Personaly if it is water tight I'd leave it alone.
The old adage "if it aint broke don't fix it" springs to mind.

 

[Damian]

To try and give a better understanding of my original statement, during the build process, all excess sealant is removed when individual components are fitted, such as a locker door for example.
During the settling period and cure time, some sealer will ooze from the compressed joint and as Dustydog has suggested, it forms an all important edge seal.

Trying to remove cured sealer, unless you use very sharp blades, and know exactly the pressure to apply to avoid damaging the caravan body, but to cut through the sealer, will end up with snagging and dragging of the sealer, which will destroy the original bond.

Also the wrong use of the wrong sealer and cleaners can in certain situations have a disasterous effect on the body of the van.
Swift vans use different sealers to Bailey, and different cleaners for for different parts of the caravan body, use the wrong one and you WILL see the panel dissolve before your eyes.
New sealer will simply not bond to old, it will always be a totallly different individual item and will not achieve anything.

As I stated originally, the ONLY long term effective way of dealing with sealer problems is to remove the whole fitting, clean all traces of sealer from it, and the van body, and reseal.
However, with the increasing use of bonding sealants, removing fittings quite often ends up with a destroyed fitting as the bonding sealer is stronger than the fitting.

The use of any cleaner like White Spirit must be done very carefully and thorughly washed after to remove ALL the cleaner.

 

[redleader]

Interested in all the previous comments, as I previously requested similar information on the "Caravantalk" Coachman forum, (see below and the answer I got at the time).
So after reading my original post and reply below, is there a "special" sealant removal chemical used by manufactureres which does not destroy the bond or not? I must admit, there are some brand new caravans out there that look decidedly secondhand because of the amount of excess sealant, and the grime it attracts.
I'm actually taking my van in for the first service tomorrow, also the shower tower crack repair I mentioned in another post, being done by PSS. I will mention it to Ropers at Catterick, to see what they say as they will have to deal with any subsequent warranty claim should the sealant fail. I agree, because of the possibility of any warrantee claim, I would only do the job myself with the permission of the manufacturer or dealer via written e-mail or whatever, and only using the recommended chemical, whatever that might be!
I'll let you know what they say.....
Regards
Don
See previous forum chat below:
"Hi, before I bought our Pastiche last year I noticed the new display vans at dealerships all had excess sealant that had squeezed out. Our new van was straight from the factory, and looked fine on delivery, but now a few months later sealant has started to squeeze out. I am talking about the outside locker doors, door retainer, things like that.
I know it is there to do a job and it is purely cosmetic, but has anyone found a way to clean it up without damaging surrounding paintwork? It does attracts road grime which doesn't clean off and becomes unsightly.
Cheers
Don"
The Reply:
"Coachman use a liquid solution to remove excess sealant, have a word with your dealer, they may sell you some.

Mine was returned to coachman for removal and reseal of door and windows, some of the boxes had "excessive" sealant material around, when I collected the excess had been cleaned up, they confirmed they use a solution to wipe off excess"