Exterior Is it Silicon or Sikaflex?

[BigSkiddy]

Was washing the van today and noticed that the white stuff where the moldings join the fiberglass is starting to get a big grubby and shrinking.

Is that silicon or sikaflex that they have used? I want to have a go at redoing it all.

 

[Bluey]

you would have to think @BigSkiddy they have used what eva is cheapest ??????????

 

[skippy]

I could be wrong but I thought they used Sikaflex Marine.

 

[mfexpanda]

I'd say silicone . Sikaflex Is more for sticking down or glueing than filling gaps

 

[Crusty181]

hey @BigSkiddy. Sikaflex is polyurethane; its expensive and awesome stuff but doesn't stick to everything ... the stuff it does stick to sticks very well, fibreglass being one of them but you need to rough the surface and prep wash first. If you don't prep the surface it won't stick properly. Sikaflex 291 is a marine filler and adhesive and available at Bunnings. I was chatting to the dealer the other day about a replacement hatch and asked him what sealer Jayco use because the Sikaflex I was using under then van wasn't sticking to whatever Jayco put on the floor penetrations. His response was the cheapest stuff going, but at the dealership they use Sikasil roof and gutter (silicone) which he said had the best all round results.

 

[Bellbirdweb]

I used the White Sikaflex marine to stick and fill the gaps when I fitted my bed end fly sail track.

Sticks like s#it to a blanket and no sign of any shrinkage so far

 

[Moto Mech]

Roof and Gutter silicone is great stuff, sticks to anything, is quite strong and flexible once set.

 

[BigSkiddy]

Thanks for the responses guys. I'll give the roof and gutter silicone a go.

 

[Moto Mech]

Ive stuck down my solar panels on roof with it, sealed up my flares with it, filled holes/gaps around van with it, I stick gauges to customers cars dash/s who dont want holes in dash etc

 

[Dean Anderson]

Question with regards to what people are calling Sikaflex. Sikaflex is a brand name and they produce lots of different products including Silicon's Polyurethanes and Butyl Mastic's. Is everyone referring to Sikaflex's Polyurethane range as Sikaflex, cause it always confuses me. Silicon being the one that sets like the clear silicon we all refer to (even though it comes in lots of colours), and Butyl Mastic being the one like runny Blu-Tac that is rubber based and gets a skin but doesn't fully set (usually grey but can come in white or black).

 

[dagree]

HMMMMM Got me thinking @Dean Anderson . I use Sikaflex 291 Marine Sealant and Adhesive. Might have to have a look on one of the tubes tomorrow if I remember and see whether it's silcon or butyl mastic.

I'd be guessing Butyl Mastic as it seems to skin rather than set!

 

[Dean Anderson]

Just looked at the website. There polyurethane Construction has 25% movement which is huge. I think everyone refers to that. Couldn't find it at my local hardware shop when replacing the hot water cover so used butyl mastic which looked more like what Jayco put on originally.

Would love to know the difference between all the silicons when they say 100% silicon and have different uses. I thought 100% meant 100%.All gets confusing for one as simple minded as myself.

 

[dagree]

One reason I use the marine 291 sika as I've used it before on boats and had no issues.... Don't want to change to something else and it leaks 20K's offshore :fish2: :eek-53:

And as you said they all claim to do the same thing but different compounds!

 

[Bellbirdweb]

I use this.

Doesn't say on the tube of its Silicone or butyl mastic, but it works well.

 

[dagree]

Doesn't say on the tube of its Silicone or butyl mastic, but it works well.

Just saved me getting mine out of the shed tomorrow to look

 

[Crusty181]

Question with regards to what people are calling Sikaflex. Sikaflex is a brand name and they produce lots of different products including Silicon's Polyurethanes and Butyl Mastic's. Is everyone referring to Sikaflex's Polyurethane range as Sikaflex, cause it always confuses me. Silicon being the one that sets like the clear silicon we all refer to (even though it comes in lots of colours), and Butyl Mastic being the one like runny Blu-Tac that is rubber based and gets a skin but doesn't fully set (usually grey but can come in white or black).

Sika is the brand, Sikaflex is the polyurathane range of sealants and adhesives Sika manufacture. Sika's silicon is called Silasil. Jayco use a silicon as their chosen sealant and adhesive. Polyurethane sticks well to some surfaces, and silicon to others. Polyurethane wont stick well to silicon, so be carful where you use the Sikaflex.

 

[Crusty181]

I use this.

Doesn't say on the tube of its Silicone or butyl mastic, but it works well.
View attachment 35296

291 is one of a couple of Sika's range of strong polyurethane marine adhesives that can also be used as sealants. 291 is the lower strength of the 2 common Sikaflex products.

 

[dagree]

291 is the lower strength of the 2 common Sikaflex products.

Lower strength of the 2???????? Does that mean I should use the stronger one on the boat?
OH hang on.... No probs as I'm about to advertise it

 

[Crusty181]

Lower strength of the 2???????? Does that mean I should use the stronger one on the boat?
OH hang on.... No probs as I'm about to advertise it

Only if its a really big boat ....... otherwise i think duct tape should be fine

 

[Colsar]

for what its worth i use sica 291, 90 percent of the time on the van, and always on the boat.