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MG Midget and Sprite Technical - Bodywork (type) question

I though about fitting a couple of 'vehicle anti vibration drum pad sheets' to the underside of my bonnet but a friend advised against it a while back.

I can't remember the exact details but he said something like the bonnet was a large sheet of un-braced metal and fitting the pads might cause it stress(?).

And he might have been concerned about them coming unstuck with and falling into the engine bay.

. Anyone know for sure about if it's a good idea to fit them?

. And if they can be fitted best position, pattern and size of pads on the bonnet?

Cheers.

Nigel Atkins

MGB's had a silencing mat glued to the bonnet and it never caused any problem.
Don't see any problem with it on a midget
O K

What Onno said.
I've used self adhesive lead flashing for sound deadening on a VW van which works well in stopping panels resonating and making doors and tailgate close with a thunk rather than a clank.
I suspect the benefits will be pretty negligible though on a Midget's bonnet underside Nigel.
Jeremy T2

They used to make those pads on ebay and even sold them for awhile on vic brit...had a huge logo of the MG with the octigon

Personally i dont see a problem i get what he is saying but all satalites will eventually fall back to earth on day....soooo

If was going to have a concern... its the prep work and the glue being used

As long as the underside is clean and the glue will bond to it plus the right kind of glue used... heat resistant and will bond to the bonnet and the pad.

Your golden no worries... maybe in 600 years the vibration will eventually take the pad off bur i seriously dont see that much vibration to make a problem

Okay...elmers milk glue like we used to use in preschool that might be a problem...

But give it a go and take some photos and let us know how you did it

My only concern for using the mat and i doulbt it would have more then a negladgle effect is can it hold heat and not allow it to transfer out as fast as if there there was no mat making the under bonnet temp rise a few extra degrees...maybe but agiqn not by that much

Prop

Prop
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Thanks for the replies so far.

The MGB has a centre cross bracing bar on its bonnet so is, er, well, braced and the sound proofing material is a matting type different to more dense and heavy sound deadening I have.

The proofing material is an insulation type and the deadening material is thin and heavy that dampers the vibrations on the metal panels.

I bought a pack of ten, 50cm x 20cm, pads and cut the pads to put in various places, I put some small off-cut strips in the uprights of the boot inner panels and when I tapped the panel even the small strip made a noticeable difference.

Nigel Atkins

Prop,
thanks for asking me to be a guinea pig :).

The pads have a sort of plastic surface that's quite compressible so I do wonder what heat might do to the pads. I can contact the manufacturer to check if the pads and glue with take engine temperatures but I doubt they'd advise on whether they'd stress a MG Midget bonnet.

Nigel Atkins

Sounds to me like they are talking rubbish. I have some on the underside of my bonnet, no problems. Four A4-ish size sheets of 3mm dynamat style stuff over the manifolds area. The idea at the time was that I wanted something to stop heat from the ex. manifold damaging the paint on the bonnet.
Malcolm Le Chevalier

Nigel, I would have thought that as the principle is that this sort of sound deadening panel is designed to reduce vibration and flexing of the steel pane, they would reduce stresses rather than increase them. But thinking about this, such materials are more often used on the inside faces of panels that surround you in he car - the door skins, floor panels, footwell sides and top and so on. That is where I have used a similar, though foil-backed product on my car.

Those cars that have sound "proofing" under the bonnet in my experience always seem to use some sort of sound insulating material like a heavy felt, rather than the anti-drumming adhesive sheets you are talking about. So it will be interesting to see (hear?) how they perform.

I think my main concern would be that the adhesive used doesn't react with and soften your paint finish. Especially prone if the paint is cellulose I think, and if the adhesive is of the Evostik variety. Equally important is that the adhesive doesn't soften with heat from the engine and begin to let go. Anti-vibration pads I have seen used a bitumen type adhesive which I think wouldn't be appropriate in an area subject to heat like the engine bay.
Guy W

I am miss informed....

I was thinking rhis was big sheet of some kind of poly type foam

I have dynamate in my car as guy describes under the carpet and behind rhe trim panals....basically the whole interior of rhe car.....and it does nice at keeping the sound deadened but dosnt control heat to well

My thoughts on putting that under the bonnet...

I would not !!! When this stuff gets warm it becomes vwry pliable ..... o used a heat gun on low to make it flow and bend around courners

Thw problem is when ot gets hot it becomes gooyyeee gooey and jusf real nasty

But what i did on mine and was cheap easy and looks great ...controls hear and noise

Wait for it...RHINO TRUCK BED LINED IT...rhat spray on stuff...

I got mone done foe $75 usa from. Pro. and ita still looks good...you can get rhe diy stuff ...its okay but rhe pro stuff is better

Give me a minute ans ill posr a photo

Prop
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Interesting Malcolm, good to hear.

My mate could well be wrong but he's not the type to talk rubbish generally and usually likes to try different ideas out..
Nigel Atkins

Here are some pics ...but its a chilly over cast day and detail is not good on this new phone

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And 1 last one

But i really do like the looks of this.. the sparkly is not glitter add on...its from the camra flash but it does help to show the texture of the rhino linner

Prop

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Thinking. Back. I did tey a small piece of that danamate in the engine bay and it just became like chewing gum once the heat got into it.

Prop
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Wow! That doesn't look like the sort of treatment you could change your mind over Prop!

Have you tried it on the underside of the wheel arches?
Guy W

And one last one that turned out decent

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Guy,
you've got the idea, I've had the soundproofing insulation stuff on a previous B so know what that is and what it does.

My Midget came without any soundproofing and the cheapest carpet set know to man but did have some sound deadening in both footwell floors.

I bought the pads to just put them on the doors when I finally get around to sorting the windows out but as I had so much of it I thought I'd try some in the boot to also see if it did anything to quieten the diff. It made a difference (but the diff whine could still be heard) so I then added some to inside of front wheel arches and the rad shroud as I thought I had a rattle there (turned out to be loose bolts). All seemed to help a little so I put more to the scuttle and footwells.

The material is very heavy but probably less so than full sound insulation plus it won't hold water so I worry less if I forget to put the hood up and it rains.

I like to hear the noise of the car but dislike rattles and vibrations so the sound deadening in small patches is preferable to me than overall sound proofing.

The advert has changed a bit since I bought it but this is the stuff -
http://www.ebay.co.uk/itm/CAR-VAN-VEHICLE-SOUND-DEADENING-PROOFING-PADS-SHEETS-10-/220649059457?hash=item335fb57481:g:kpQAAOSwbsBXpEoe
Nigel Atkins

Prop,
thanks, interesting.

Do you think it would/did stop or lessen vibrations from the bonnet?

I don't want to heat insulate my bonnet as it gets warmer enough in summer and needs cooling, another reason I didn't want soundproofing (insulation).
Nigel Atkins

Good question nigel

If its just the bonnet id think lessen but on mine i did the DIY spray on linner on the entire engine bay area as it was hidden and had a pro do the bonnet lid

But there is no sqeaks or rattles comming from the various body panals

Prop
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Guy ... i wish i had ... ive got some other ratle can stuff thats held up well

But yeah that rhino stuff is permanate and can be painter over ...ive got my hard top front spoiler and radio consel gage all sprayed in the same stuff

If i ever do another midget...id rhino the bottom of the car the boot the cockpit the engine bay inside the doors and a few other odds and ends. Then paint / powder. Coat the rest

I still want to rhino my rocker panals below the chrome trim and my roll cage behind the seat

But i do love the stuff .. the 4x4 mudding trucks really liks the stuff also...its almost bullet proof and you dont have to have the panals perfect this stuff fills in all kinds of scratches and imperfections

The secrete to rhino is cleanliness and preperation for it to do well the area to be applied has got to be spotless clean ...like white glove clean otherwise its a huge freaken mess and will just peel and blister off... ive got an entire day cleaning the under side of that bonnet before i ever gave it to the pros to spray

Also...buy cheap hardware and screw it into any holes you plan on reusing rhen use a razor blade to cut the rhino away fromthe hard ware so you can use the threaded holes...thats a mess if you dont

Prop
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Sorry Prop I won't be spraying Rhino Liner, I dislike things like glues, adhesives and paint even more than I dislike grease, oils and lubricants.

I'm not sure the Rhino Liner would fully achieve what I'm after and nowhere as easy as putting on a few small self-adhesive patches.
Nigel Atkins

I bought some automotive specific self adhesive sound deadening pads from a bodyshop supply company and they are OK on the floor panels, but I put one in each door and after a couple of years, probably due to summer heat, they buckled and started to slide down the door, to the extent that I couldn't wind the window up or down. I had to strip the doors and get rid of them, something I could have done without. So be careful putting anything self adhesive under the bonnet.
Bernie Higginson

One of mine refused to stick to one of the doors, but that was due to the accumulation of crud and grease all over the inside of the door! :-)

Malc.
Malcolm Le Chevalier

My P6 has a massive sort of felty thing stuck to the underside of the bonnet. I assume it's fireproof :s the bit above the dashpots is soaked in oil from a previous experiment with ATF in them...

Midget is too loud in all directions to benefit from sound deadening, though I might be tempted on the axle cover part to try and reduce the small amount of diff whine...
Rob Armstrong

Bernie and Malcolm,
I note your advice and comment ( :) ).

Rob,
I hope I've not misled you about the axle noise, I think the axle casing is already too thick for any pads to dampen the vibration much more, perhaps surround the axle in a bale of insulation or insulate your ears with a thick woolly hat pulled well down and doubled-up over your ears.

. . . or of course a change/refill change of axle oil :)

As you probably found ATF is a bit too thin for the dashpots try 90 weight gear oil you'll find that'll make things very smooth.


Nigel Atkins

ATF was rubbish. 20/50 worked best.

I was thinking on the rear deck rather than the axle casing. But it's only a small whine.
Rob Armstrong

Rob,
I put mine on the boot floor, rear deck (if you mean the bit below the plastic boot/cabin divider), boot lid, rear wings and side support panels (the ones with triangular holes). All were cut down pads or part of.

I thought the rear deck bits might quieten the diff by indirect damping and by just having another dividing layer but I can't say it did.

The boot is a good sound chamber so the pads worked well there especially on the side support panels.

I also put some on the inside of the front wheel arches and rad shroud.

I would say the pads are a success but of course the more noises you quiet (or vibrations dampened) the more you notice smaller noises elsewhere but overall still worth doing.

Course it would add weight to a competition car.

Did you try 90 gear oil, I think you'd like the results.
Nigel Atkins

Well I tried contacting Wayside Adhesives twice through their contact form on their website without reply but went I used the ebay contact at 7pm Monday night I got a reply from Wayside 3 hours later 10pm (the power (fear of?) of ebay).

They confirmed that the sound deadening pads I have that they supplied will be alright to use on the underside of a bonnet that's painted with cellulose and allowing for the engine heat.

I've not got around to putting them on yet but will report when I do after road testing.
Nigel Atkins

Today I fitted the sound deadening pad to the underside of my bonnet and it made a noticeable improvement to reducing the resonating sound from the bonnet.

I cut one 500mm x 200mm pad in to four pieces to spread the loading(?).

I was quite surprised that it made the bonnet feel noticeably heavier but I suppose most of the weight is away from the hinges, the full pad only weighs 310g (11oz).

I think I might have got away with only using half to two-thirds of what I actually used but it's on there now.

Also after (of course) fitting I noted that one of the pads was directly above the thermostat housing so I see if that was a bad idea later perhaps.
Nigel Atkins

Should be interesting to see what happens

I wish i had worked on my car today...its nice out

Prop
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This thread was discussed between 02/01/2017 and 15/04/2017

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