best adhesive

[byroncobra]

Fellas

I stuck the aluminium side vents on my car to the body with a bit of folded ally and sikaflex but it's not holding real well to the glass (sticks real well to the aluminium)

My next try was going to be 'hairy bog' ie a glass epoxy filler.......any better ideas?

G

[boxhead]

I would glass in the alloy brackets to the body work.
Not just with the "hairy bog" (Gorilla snot) but instead with fiberglass sheet and resin.

[Merv and Sharon]

That's what I did Greg after a few attempts with the Sikaflex with the same results that you seem to be having.

[Zedn]

Its interesting that you are having trouble with the sikaflex.

What type did you use? Did glue it so there was room for the glue and not clamped tight?

I glued my door skins on to the intrusion bars sikaflex. I redid the doors a couple of weeks ago and there was a dab of sikaflex i had to remove. The only way i could get it off was with the grinder it bonded so well.

Glassing in would be best for that application. Dont use to much though or the body may warp where the fibreglass is.

[Rob. Smith]

Boxhead Gorilla snot is contact glue....yellow and sticky ! Gorilla hair is the bog stuff. I wouldn't 'glue' the vents in. In case you might have to remove them for some reason or other. What about self tappers or nutserts . I think the original cobra vents were riveted in. That might be a good alternative as well.

[Outwest34au]

Originally Posted by Zedn

Glassing in would be best for that application. Dont use to much though or the body may warp where the fibreglass is.

I am told the warping occurs when the next coat of glass/ resin is too HOT.
When glassing gradually reduce the MEKP in the next layer to prevent bunching. IE, if you start with 2.5% MEKP the next layer should be 2%, then 1.5% etc. (or use .25's if you like). The main thing is not to increase the MEKP above what was used in previous layers.

Glass the brackets and screw or rivet the actual vents will be the way I go. In my case I want to be able to remove the vents for ease of service/ removal of brake lines going to the M/cyl and it's way easier for me to get to the solenoid wire through the vent hole.

[byroncobra]

I'm thinking that maybe I didn't clean off the waxy stuff from the glass
to get a good bond.

Don't really want more holes in the body with screws etc and getting in there now with resin and cloth would be difficult. Thanks for the ideas though.....

Might try again with a good primer first.

What ended up sticking merv?

Greg

[Outwest34au]

Ahh, the old waxed resin trick,
Resin has wax added so it isn't sticky when dried. When it is fresh (or green if you like) it can be glassed over though.
When it has cured properly you must grind or aggresively sand it then clean thoroughly with acetone to avoid seperation.

[byroncobra]

Ok, I'll sand first......that'll save me another tube of sika. Bloody stuff doesn't last too long after you open it...
Thanks

[Merv and Sharon]

Greg, I glassed the ally in and then just screwed the vents in with small screws top and bottom.

[gjkrv8]

I used sikaflex on my aluminium angle brackets (with nutserts) for my side vents. Has held pretty good. Even used it to stick on the front Brake vent grilles, worked a treat.

Must have been lucky as I didnt do any special prep.

You're right though, the tube goes off pretty quick.

Rgds

Gregg

[400TT]

Make sure it is the adhesive type of Sikaflex.

My guys ensure they don't use it in big blobs on our adhesive jobs, use the traditional builders "W" type pattern so that you get plenty of surface area for it to cure.

We also do not stress for quite a few days, even leaving it a week to fully cure. It can take a long time to fully cure if conditions are not great.

Certainly wouldn't hurt to also score the surface with rough sand paper to help with adhesion.

Normally the problem is getting the glued item back off. The only way of removal is to saw your way through the Sikaflex.

We use Sikaflex to hold large oil coolers onto body panels.

[Ant]

The side louvers I think used a cheesehead machine screw to hold the louver to the angle brackets. On a fibreglass car either glass the brackets on with polyester resin and csm matt or cloth sanding the area well, or use epoxy resing and csm matt or cloth, epoxy is a stronger adhesive compared to polyester resin.

[Rick Parker]

Different expansion rates will cause issues between the aluminum and fiberglass. Best solution is to use a flexible Structural adhesive such as something made by Lord or 3M. They are 2 part, often able to be used with a caluking type gun or similar on a smaller scale. Working time can be up to an hour or as little as 5 minutes. Find it a a Paint & Body Shop supply shop. This is how they bond the various parts of a Corvette together. Finished product is generally stronger than the parent material.

[07cob]

Greg

Originally Posted by 400TT

Make sure it is the adhesive type of Sikaflex.

This is the key as well as having a sufficiently rough surface. Sika make a number of caulking products as well as glues. The adhesive type is 11FC. Great for a number of Cobra applications.

Cheers

Geof

[sambo]

Thanks Geof, I've added that to the Easter shopping list!

[Ant]

A simple way is to drill holes in the mounting face of the angle brackets, rough them up and cover with glass matt etc, so the bracket is encased in resin etc and has resin right through the holes eg 1/4" holes, and wont fall off.

Aluminium and fibreglass arent really compatible unless you do the above which is only one way, there have been some excellent tips in this post on professional products eg used in corvette manufacture. Aluminium is often used in boat building etc as a mould because fibreglass doesnt stick to it.

Another way would be to glass up some angle brackets between two pieces of alloy 90 angle space them the required thickness and then you have a bracket of the same material as a glass cobra!

[ptrefry]

Plastibond sticks like Sh#t to a blanket.

[07cob]

Originally Posted by ptrefry

Plastibond sticks like Sh#t to a blanket.

A turer work has never been spoken.

My dad introduced me to Plastibond a couple of years ago. Now I buy it in bulk as it has so many applications. And it goes off like a rocket. Very similar to body filler.

The other glue I really like is JB Weld. It sticks like ... Plastibond. Probably not much good for the side vents though.

Geof

[lnfletcher]

I used Evercoat Maxim urethane adhesive.
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