Gluing on new rubbing strake

[Barrel Rider]

Hello I'm wondering if anyone with experience fitting a rubbing strake can help me.
I attempted to fit a new strake to my searider today. I was doing it in 2 pieces so started at the bow and worked back, rollering it very firmly. When I finished sticking it all on and went back to the bow to roller it again, it had started peeling away from the tube. I realised the 2 coats of glue I had brushed on the strake hadn't bonded to it at all and it all came away very cleanly The glue had bonded well to the hypalon and to itself, just not the epdm strake.
Not to sure what I did wrong, I'm wondering if I applied the glue to soon after cleaning the strake with thinners? or hadn't prepped the surface of the strake adequately, I sanded it by hand, should I use a grinding stone on the dremel instead?
Thanks for any help

[CherMac]

No advice for you, sorry. But man, that must have really sucked.



My luck would have been the strake gluing itself together.

[rik_elliott]

What material is the strake made from? Which glue did you use?

If it was made from pvc then hypalon glue might not grab it too well. I've heard of people bonding pvc and hypalon by using pvc glue on one side and hypalon glue on the other and prepping each side as appropriate.

[Barrel Rider]

the strake is made from epdm and I used 2 part hypalon glue

[foxinsox8]

So assuming EPDM is a similar rubber product that is suitable for Hypalon glue, you need to do the following. Ensure conditions are at less than 75% relative humidity. Mask the area on the boat hull. Heavily abrade that area... it needs to be like suede! Use 60 grit... best way is to use a dremel for high speed sanding. Abrade the rubbing strake similarly.Mix the glue and wait five minutes. Apply a thin coat of glue to hull and to strake and wait 30 to 40 minutes until it is completely dry. Apply a second coat and wait about 20 minutes until it is barely tacky. DO NOT HEAT the glue (that is only for the PVC glues).
Now apply the strake. stretching it a but as you go. Use a steel roller stitcher if you have one or apply pressure with a spoon, screwdriver handle... whatever works. The bond is mechanical so serious pressure is essential. Remove masking tape If the glue still won't take to the EPDM strake try using the PVC version. You can either crosslink the Hypalon and PVC glues but my local inflatable glue manufacturer says their results are the same using just PVC as with using the (fussy and complicated) cross linking method. Best of luck. Let use know how you get on.

[Barrel Rider]

Thanks that's very helpful. I don't think I abraded the strake enough the first time.
I used an eraser wheel on a drill to remove the glue from the tubes today which worked really well, so when the weather is good enough I'll have another shot at it.

[909]

There's a video from Alfred Montaner from Luxury Rib Tenders LLC based on Florida USA that shows the entire process in a factory on Youtube

[ribraff]

If the strake is made of EPDM you need to apply a primer before bonding. This is made up of adhesive and hardener mixed with a 50% solution of toluene thinners and is applied to the strake 24 hrs before the normal procedure of two coats on each surface.

[cgoing]

Without it being prepped(scuffed) enough, it will not stick. Too much and you can damage the tube and cause leaks. It is a delicate balance. It also needs to be thoroughly cleaned before and after prep with proper solvent. toluene is best, if toluene not avail, use acetone and add an extra cleaning wipe.
Follow glueing directions for the glue you have. Not all glues have same time cycles.
I buy glue from Pennel in bulk and the timing is different than most adhesives sold to the public in smaller quantities.
Bostik, polymarine, Clifton all have different timing of glue cycles.

[Barrel Rider]

Originally Posted by ribraff

If the strake is made of EPDM you need to apply a primer before bonding. This is made up of adhesive and hardener mixed with a 50% solution of toluene thinners and is applied to the strake 24 hrs before the normal procedure of two coats on each surface.

Ah thanks I didn't know to do that first. I'm not sure where to buy toluene, do you know if I can use the hypalon solvent, primer, like what ribstore sell instead of toluene?

[Barrel Rider]

Thanks for all the help, had really good weather this weekend with low humidity so was able to have a second attempt. Followed all your advice and it looks to have bonded securely this time. I think the two main differences were making sure it was thoroughly abraded and I applied all the glue under a lean to out of this sun this time. Trickiest bit was probably the D tube round the bow which needed a ratched and wedge to keep it all in place.
Just have to glue the lifeline holders back on and replace the tatty Avon badges and that will be it all complete.
Thanks again for the help
Before and after pics

[Aquaplanning]

That looks good! The rubbing strake is the next step for my project, and quite frankly I'm a bit scared because I have to put an eye pleasing curve in it.