Ranger hood needs anti-flutter foam .... proven solutions for DIY?

[98v70dad]

I just had a junkyard hood put on my 96 ranger and all of the little blobs of foam between the hood sheetmetal and skeleton below are disbonded and separated. Those little blobs are called anti-flutter foam (just learned that today) and they are there to support the thin sheet metal and also keep it from vibrating like a drum head on the highway. They have to be soft and let the sheetmetal expand or contract in temperature changes so the hood doesn't get wavy.

Anyhow, the correct stuff is easy enough to find but its pretty expensive and it requires a $100-ish cartridge gun to apply it. It is also tricky to apply. Does anyone know of a DIY solution that works and doesn't cost a fortune? I've already ruled out great stuff construction foam. It gets hard and the expansion can't really be controlled.

My best idea (I think) so far is wedging small squares of closed cell foam between the old blobs of foam and the sheet metal to fill the gap. Harbor freight shop floor mats look to be about the right thickness and they're cheap. My only concern with that is it may hold moisture between the foam and the metal if it gets wet.

I'm hoping an auto body guy can give me some advice or ideas.

 

[franklin2]

Body seam sealer would work wouldn't it? That stuff the factory uses on the seams after they spot weld them together. Simple silicone caulk would work also. Just pry it open with a putty knife a little bit and squeeze some in between the hood and the bracing.

 

[superj]

Iwas thinking the same about the silicone caulk, but not having experience in this stuff, i figured i would just read along

 

[alwaysFlOoReD]

There is closed cell expanding foam used for residential home window and door installation. Comes in cans for about ten bucks. It's flexible, and doesn't warp the plastic frames on windows...
It sticks good on a moist surface. Being that the hood and frame are not an enclosed surface I wouldn't worry about over expansion. Make sure the two surfaces are clean, spritz some water in between, and put in some foam.

Edit; I've never done this. But have installed hundreds of doors and windows.

 

[98v70dad]

There is closed cell expanding foam used for residential home window and door installation. Comes in cans for about ten bucks. It's flexible, and doesn't warp the plastic frames on windows...
It sticks good on a moist surface. Being that the hood and frame are not an enclosed surface I wouldn't worry about over expansion. Make sure the two surfaces are clean, spritz some water in between, and put in some foam.

Edit; I've never done this. But have installed hundreds of doors and windows.

Thanks, as I said, I've already ruled out construction expanding foam. I spent a lot of time reading body work forums today and everyone who tried it said it didn't work.

 

[98v70dad]

Body seam sealer would work wouldn't it? That stuff the factory uses on the seams after they spot weld them together. Simple silicone caulk would work also. Just pry it open with a putty knife a little bit and squeeze some in between the hood and the bracing.

It has to fill the space but not glue the parts together. I'm not confident that seam sealer or silicone will do that. I think it would work much better than expanding foam, though. Other than the foam rubber shims I thought of either of those might be an option.

 

[alwaysFlOoReD]

Thanks, as I said, I've already ruled out construction expanding foam. I spent a lot of time reading body work forums today and everyone who tried it said it didn't work.

Ok. The stuff I'm talking about doesn't get hard. It's cures to the consistency of a marshmallow. But if others have tried and it failed that's good to know...

 

[franklin2]

It has to fill the space but not glue the parts together. I'm not confident that seam sealer or silicone will do that. I think it would work much better than expanding foam, though. Other than the foam rubber shims I thought of either of those might be an option.

I would think you would want it to glue the two pieces together to keep the hood from bouncing. I would not want anything too thick or did not have enough give in it, or the hood could look wavy. As you said, it bounces up and down and is not very strong without the bracing being attached.

On my 64 impala they used a old tar like substance, similar to some old type of seam sealer. It had dried out and that hood bounced also.

 

[rubydist]

I would try the seam sealer first - the kind that gets firm but not hard. I put that in the bedside seam on the 66 F100 and it has never gotten hard enough to sand off the part that I didn't get troweled smooth enough when I first put it on.

 

[98v70dad]

Ok. The stuff I'm talking about doesn't get hard. It's cures to the consistency of a marshmallow. But if others have tried and it failed that's good to know...

The heat bakes the hood and eventually hardens it. Underhood temps in the US south can get pretty high in the summer.

 

[dvdswan]

Be careful prying between the hood and inner hood. I would use a something like thick paper/poster board so you don't ding the hood.

 

[19Walt93]

I second the motion in favor of seam sealer and also recommend caution when prying the panel up to squirt it in the gap.

 

[98v70dad]

I second the motion in favor of seam sealer and also recommend caution when prying the panel up to squirt it in the gap.

The gap is large. Surprisingly large. Like 1/8 to 1/4". No prying is necessary.

 

[4x4prepper]

Do not use expanding foam or normal sealant, it is not mean to be used with the high heat. Get fire block sealant, it can take the high temperature while remaining flexible and if it gets set on fire it chars and puts itself out. I think the stuff I buy at HD is 3M and it is colored blue. I use it to seal my thimble for my wood stove and triple wall pipe If you do any amount of new construction, you end up using it as a fire block in ventilation systems and in between partitions and such as it is required by code in many places.

 

[Eddo Rogue]

plumbers putty?