Soundproofing problem

[Gypsyjoss]

This time, last year I bought some expensive acoustic insulation foam and a large expensive can of spray (the bee's knees and great to use) contact adhesive. Took this out to Greece and fitted Ok - for a short while. All the overhead pieces dropped off and the side pieces are sliding. I've been advise to refix with normal contact adhesive like Evostik. But the old adhesive is on the two gluing surfaces and I see no easy way to remove it. Is there a way, do I need to remove it? Do I have to start a gain with new foam?

Note: Old sections which I didn't replace are still secure!

Cheers

 

[30boat]

If you can clean off the old glue try a polyurethane adhesive, Sikaflex type.
On my boat I just used screws.

 

[sarabande]

whatever adhesive you consider, check that it does not melt at around 40c. Happened to me with velcro tape stuck on a LandRover in Saudi; the tapes just fell off, leaving gluey string hanging down.

 

[alahol2]

I used ordinary PVA adhesive on mine about 4 years ago. Plus a couple of screws through overhead ones. Nothing has moved so far.

 

[macnorton]

I use this stuff and have never had a problem, but I am in the UK?

http://cgi.ebay.co.uk/TRIMFIX-SPRAY-ADHESIVE-STRONG-HIGH-HEAT-RESISTANT-/260723701820?

 

[Viking]

You can buy special plastic fixing 'washers', they look abit like large 'penny washers'

 

[Scotty_Tradewind]

I used s/s penny washers with round head screws for the areas above the engine as the spray glue I used began to give way.

 

[Trundlebug]

I've used a tube of Evo Stik "Sticks like S**T" applied from a skeleton gun.
It's suitable for high temperatures, sticks quickly, is quick and easy to apply, ideal. It's even waterproof.

It's been holding 1m square panels of thick (and heavy) sound insulation on the bottom of my engine hatches for over 12 months now, without any problems.

I Got it from Screwfix, but it's also available in builders merchants etc.

 

[PeterGibbs]

If you can clean off the old glue try a polyurethane adhesive, Sikaflex type.
On my boat I just used screws.

Refix exisiting soundproofing using mastic glue and screws with washers at regular intervals to secure. Mine still in place after 12 years!

PWG

 

[charles_reed]

PU glues of various kinds do the job - unfortunately the soundproofing in overhead areas then delaminates with age (the metallised pvc comes off leaving the metallisation behind), so one ends up with mechanical fixing.
No need to break the bank with the Sikkens products, there are any number of more realistically priced PU adhesives out there, produced by people like Bostik, BASF and Henkel.

 

[Gypsyjoss]

Do screws and washers reduce soundproofing?

Thanks for all your replies.
I have resisted the screw and washer solution for fixing soundproofing because gut feel suggests this would reduce the effectiveness but no doubt I'm being too purist and the effect is negligible!

 

[Bobobolinsky]

There are some fixings called Prespin's, which are ring nails with a large flat head. You glue the head to a flat surface with grip adhesive, push the foam onto the nails and then a large diameter plastic washer is pushed over the pin and the pin cut to length. A plastic cover is then pushed over the pin to make it smooth and safe.

 

[PeterGibbs]

Thanks for all your replies.
I have resisted the screw and washer solution for fixing soundproofing because gut feel suggests this would reduce the effectiveness but no doubt I'm being too purist and the effect is negligible!

The losses incurred through the un-proofed parts of the engine compartment, and air leaks in and out (otherwise how does the engine run?!) vastly exceed the influence of a few screws..........

I think you knew this, but just wanted to prod us a bit.

PWG

 

[Gypsyjoss]

Quote:I think you knew this, but just wanted to prod us a bit.

Yup!