Preparing fibreglass for new sealant

I am going to replace the sealant around all the fixtures on the roof of my 2008 Devon. First is it safe to get onto the roof? I weigh 95kgs. Secondly having scraped off the old sealant, what should I use to clean the area before applying new sikafkex sealant? Thirdly, Sikafkex EBT sealant from Screwfix is half the price of the 512 from caravan accessory shops. Is there any difference? Thanks.

Hi FOA

I think I would suggest having a word with your dealer's workshop manager. I don't know the details, but I do know ours use a cleaning (preparation??) product that isn't generally available except to the trade.

Could be worth a phone call before you buy the wrong stuff?

Sorry I can't give specific help.

Dave

Hi FOA, re your second point white spirit was recommended by workshop person at our M/H dealership. Regards

Acetone might be better, no residue unlike white spirits.

White spirit works for me, make sure your sealant is in code and the outside temperature is warm enough for the sealant to cure.
I made the mistake recently cleaning and resealing a small area only to find the sealant still sticky a few days later and after last nights heavy rain,ruined and covered in sand.
I wish the sealant makers would produce a smaller  tube as I rarely use the full tube and waste the unused sealant.
Boaby

White spirit will certainly leave a slightly greasy residue and should not be used if you really want not to have to do the job again in a couple of years. Acetone, wiped on and wiped off quickly, with kitchen paper, is a better bet. However, ask Sika.
I've had fibre-glass cars for 45 years, btw.

Regarding choice of Sika sealing product, I'd ring their technical helpline, describing exactly what your task is, rather than risk uninformed opinions, some days one just has to pay the higher price for the correct product.

White sprite is only used if normal cleaning products are unsuccessful , I.e to remove traffic film, brake dust etc. once the area has been cleaned and dried, the sealant is applied.
Boaby

Last week I was told and used meths

I personally would not go on the roof of a modernish AS, the older ones pre 2001 OK. I know there will be those on here that will differ but then again it's my roof and money I am a mere 81kg

PLOUGHLIN wrote:Acetone might be better, no residue unlike white spirits.

Agree completely. We have a fibreglassing division in our company that deals with the modern fiberglass roofing systems. Only Acetone is used for preparing where sealants or joints are to go. Using anything but the correct specific to the job materials is dooming the job to fail. 

Go to any roofing material  supplier and you should be able to buy in as small a quantity as 1 litre.

All I've ever done is used a credit card (as a scraper) as advised by Auto-Sleepers to dig out & remove any old sealant, before applying a new bead, never had any trouble here.

I save all my bank, store cards, Apple cards etc for this purpose.

CC

I replied to your post at 6:36 yesterday (seven and a half hours after you posted the question) but see from a parallel thread you started on the same subject that you had already done the job by that time! You don't hang about.

Did he listen to any of us?

PLOUGHLIN wrote:Did he listen to any of us?

That's a sticky subject; my lips are sealed.

Yup, I read them all. Liked the tip about the credit card. Been cracking on today and looks like it was a failure of sealant around the roof light over kitchen that was causing the problem, plus cracks in the sealant on rear panel upper joint plus lack of sealant between rear and side skirts. Have not climbed on roof but managed to reach everything with tall step ladder. Thr Sikaflex 512 is great stuff, awaiting delivery of some more tomorrow plus the official Sika cleaning agent. Thank you for all your comments!