Help please with a adheshion question?

Hi im new to the forum and have decided to ask on the wealth of information here to hopefully find a answer to my quiery?

I have a quicksilver 670 and am looking to add some exra features, i want to put a shelf/ compartment across the roof inside abouve the window line to house some radio gear. I have some upvc roofing trim/ shuttering or soffit board you might know it as in large sheets and smaller prefab 90* angles and such and need to find a strong adheasive that i can use to bond it cleanly to the roof with.

I like this upvc because it has many good qualitys.... Its super light.... Durable and tough...... Wont rot or deteriorate....... And has a gloss white finish the same as my boat as far as i can find Online its upvc but i think it may be just pvc. Its got a hard face and a foam like density filled core with a hard backing. Ive tried to bond two pieces with pvc plumbing pipe weld but it doesnt take and nore does it hold with grip fill

So im looking to bond upvc (maybe pvc) to gelcoated fibreglass??? Needs to be able to withstand the expantion and contraction of a grp boat and the General actions of a boat..
Have looked at marine tex flex set but its not readily available here in uk
Help please??

 

Dont know...but the adhesives like sika flex or 5200 develops a tremendous bond.

Do a test on a piece.

Some plastics need primer or the flame treatment to bond...google the terms

 

I have used epoxy to glue other materials to PVC rigid pipe before now. However that was for limited service conditions. It (epoxy) does not work on plasticised PVC ie with an additive in. The added plasticiser inhibits a true bond. I note there is an Araldite supposed to glue PVC and this should be in the Araldite epoxy family. I tend to use the slow setting commercial ones (Araldites) which are good - laying up carbon guitar backs.

The Sika products are pretty good and should be worth investigating. Make sure the surfaces are really clean. Possible even very fine wire wool to very lightly abrade the surface. Degrease and clean with acetone prior to applying the adhesive. Even naturally oily woods, ie rosewood and ebony need this treatment to glue!.

 

Thanks guys thats all good food for thought, im still open to surgestions because i want to do this once and once rite! If you catch my drift

 

UPVC and PVC are both the same thing, except UPVC hasn't any "plasticizers" added. These plasticizing agents allow the PVC to be more flexible.

Both materials can be epoxied, if the surfaces are "caramelized" first. Epoxy bonds aren't great on this product, nor any other adhesives. Welding or chemical welding being the preferred choice for joining.

For your application, epoxy will work, if caramelized, as it's not under heavy load and if you make the contact surfaces fairly large. It can also be mechanically fastened to cleats, bonded to the 'glass roof. This would be my route, as it permits easy removal is you need to make repairs or R&R a piece of equipment.

 

Methyl methacrylate aka ITW plexus will bond all manner of slippery plastics (vynils, ethylene, propylene. Etc. to FRP as long as the surfaces are clean.

 

Plus it cures in about 10 minutes versus more than 24 hours for 5200/sikaflex. Caveat being, it shouldn't be used where immersed in water and only has minimal flexibility so it's not a sealant or bedding compound.

 

Aha thanks for all the feedback, it can be a bit of a daunting world when searching the net for products with all these different products, theres alot out there and alot that wouldnt work so thankyou all for your time and experienced knowlege. Ive ordered some sikaflex as it will seal as well as bond so i have a few other jobs in mind for it. Il post some picys of the finished job when im done if anyones interested

 

That would be good Quicksilver.

Froudian Slip - the methyl methacrylate glue in the UK is called Tensol (at least best known brand) and is really only any good for acrylic (Perspex/Plexiglas) to acrylic bonds. Tensol is closer to 24 hr set in my experience but gives a great bond especially where clear to clear sheet is joined. Lots of exhibition cabinets made this way.

 

Tensol cement is a clear liquid that is indeed methyl methacrylate with dichloromethane as a solvent. You are correct that it is used for bonding Perspex/acrylic. You are perhaps not familiar with the plexus line of products which are a methacrylate in a two part formulation that must be mixed., the resulting compound is viscous and thixotropic and milky white and will indeed bond dissimilar items including Delrin and olefins to FRP quite well. Jenneau uses this stuff to tab in bulkheads on some of their sailboats even. In my experience it will bond damn near anything short of maybe HDPE or PTFE.

 

Thanks Froudian Slip. I have used a couple of acrylic 2 part adhesives but mainly for bonding onto acrylics with other acrylics. Not sure we get that Plexus over here but there are other varieties available. I was not too sure about external ie UV exposure with acrylics. No problem internally, even some aircraft boys use them. Be interesting to see where Jeanneau bond with it, internal or external.

Good to know you have good experience of the bond strength. Although I have bonded PP and other polymers, not all have done well in practice. The normal culprits PP, PE, Acetal, Nylon 6 and 6/6 are all tricky. Some others are fine including Nylon 12 so the exact make up chemically matters a great deal.
Thanks for the heads up.

I suspect there will be no dichloromethane any more in Tensol, but it will have been substituted with another solvent as it (dichloromethane) was effectively banned in the EU in 2010. That is why our paint strippers don't work on 2k paints the way they used to!.