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Need help strengthening door panel

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I am currently trying to make my doors more rigid. I was going to use 1/8" thick aluminum bars but I do not want to weld them to my door skin as I will have to repaint my car. I was told I could use pl premium but I have no way of clamping them down for 24 hours.

Here is my solution

I was going to just coat the inner skin of the doors with multiple layers of fiberglass. To get this to stick to the skin I am kind of clueless. Would sanding the door with a heavy grit prior to fiberglassing be enough?

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Try gluing the cross supports as you already thought of. I don't think you will need to clamp, just brace them in place until the glue drys.

Otherwise I recommend about 4 layers of dampener mat.

The fiberglass will not stick to the metal for long, the first temperature change and the fiberglass will seperate due to different rates of contraction/expansion.

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Try gluing the cross supports as you already thought of. I don't think you will need to clamp, just brace them in place until the glue drys.

Otherwise I recommend about 4 layers of dampener mat.

The fiberglass will not stick to the metal for long, the first temperature change and the fiberglass will seperate due to different rates of contraction/expansion.

How do you recommend I brace these in place?

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Try gluing the cross supports as you already thought of. I don't think you will need to clamp, just brace them in place until the glue drys.

Otherwise I recommend about 4 layers of dampener mat.

The fiberglass will not stick to the metal for long, the first temperature change and the fiberglass will seperate due to different rates of contraction/expansion.

How do you recommend I brace these in place?

Blocks, wedges, shims or any other method neccesary, the bracinging is only temporary until the glue drys.

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Tell me more about the setup. What mids are you using, how many, where are they being located, what exactly is it you are trying to brace?

I wouldn't do 4 layers of deadener. Each additional layer is progressively less effective. By the 4th layer you are wasting a lot of time and money for little benefit.

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If 4 layers is what it takes, then do it.

I personally am a fan of as many methods as possible to stop panel resonation. ie, bracing, supports, lamination, whatever it takes. When Theres no other option than several layers of damplifier, well, do the damplifier.

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Tell me more about the setup. What mids are you using, how many, where are they being located, what exactly is it you are trying to brace?

I wouldn't do 4 layers of deadener. Each additional layer is progressively less effective. By the 4th layer you are wasting a lot of time and money for little benefit.

I talked to Dom over at SDS and he said that deadener is not what I am after. My panel literally flexes lol. We are not talking rattles. He told me the only effective way to do this was to use those aluminum bars. He told me to weld them but that would require a repaint which is not going to happen. The mids are not the problem, it's the subs. 4 18s on ~ 10kw rms just destroys the panels. He also told me that for my particular application I am better off not using a deadener as it will take away from spl in most cases. He told me to use a mass loaded vinyl to get rid of exterior noise as well as closed cell foam.

I am trying to brace the exterior panel of my door from the inside using aluminum bars.

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I hear you about the door flex, I am in the same boat. (sort of)

Heres a link to what I had to do to to my doors, for MY purposes. As you will see it took several methods combined to control the madness. I only had to add multiple layers of deadener along the top edge of the door in MY case, due to NO OTHER WAY to support along the window span. Everywhere else on my door only has one layer. I have a layer of CCF and MLV in there also. other notes: I used 30 ft butyl rope between the outer skin and factory cross supports, and used 12ga aluminun plate to seal all the door openings.

Go to page 7 for pictures, if its not alreay on that page.

http://www.soundsolu..._90#entry688856

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I am ALSO NOT suggesting that you try reproducing what I did, obviously because we have different goals. I am simply stating that I think you really just have to try different things until you get the result you are after.:)

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I am ALSO NOT suggesting that you try reproducing what I did, obviously because we have different goals. I am simply stating that I think you really just have to try different things until you get the result you are after.:)

Thanks for the input! I was going to put 2 10s in each door but depth limitations killed the plan =(. Thats sick bro I betcha those get down low.

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I am ALSO NOT suggesting that you try reproducing what I did, obviously because we have different goals. I am simply stating that I think you really just have to try different things until you get the result you are after.:)

Thanks for the input! I was going to put 2 10s in each door but depth limitations killed the plan =(. Thats sick bro I betcha those get down low.

They can if I want (get low) but I am finding for my purposes (SQ) that they are cleaner sounding crossed alittle higher. I am even experimenting with them playing into the mid range. I am amazed how well the 12" Aura reaches, Its (only one) ear blistering crossed @800hz 24db on the top end. not that I think thats really what I am after, but they can WAIL if asked to.

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combine the suggested methods. put down a layer of deadener as a base to get good adhesion to the panel. then put on some of the aluminum bars followed by another layer of deadener to keep them in place. sort of like fiberglass, except instead glass fibers for reinforcement you are using aluminum bars, and replacing the resin adhesive for a foil backed butyl rubber.

no welding required. no rattles because they are sandwiched between deadener. and most of the rigidity should transfer through to keep the panel from flexing too much.

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combine the suggested methods. put down a layer of deadener as a base to get good adhesion to the panel. then put on some of the aluminum bars followed by another layer of deadener to keep them in place. sort of like fiberglass, except instead glass fibers for reinforcement you are using aluminum bars, and replacing the resin adhesive for a foil backed butyl rubber.

no welding required. no rattles because they are sandwiched between deadener. and most of the rigidity should transfer through to keep the panel from flexing too much.

Basicly what I did to my outer skin with the butyl rope, factory cross supports and deadener. It works great other than along the top edge of the outer skin (along the window edge). Due to no support up high and no way to install one either. Thats where I did the extra layers of deadener because the panel was still flexing/vibrating/resonating after ALL other said methods had been employed.

Apologies for being so vague with my multiple/4 layers comment.

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If 4 layers is what it takes, then do it.

I personally am a fan of as many methods as possible to stop panel resonation. ie, bracing, supports, lamination, whatever it takes. When Theres no other option than several layers of damplifier, well, do the damplifier.

By the 4th layer you are gaining little to no benefit by way of constrained layer damping and basically just adding mass to the panel.....in which case, there are possibly cheaper and more effective means of simply adding mass. Hence my comment.

As to the original question; If flexing the door panel is the problem, is there a means by which you could seal off the inner door panel so that less pressure is reaching the exterior door panel? I think that may be a better option than trying to re-engineer the door structure. You may even by able to incorporate some form of bracing the exterior door panel into the system.

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Definetly cheaper ways to add mass but when ALL other methods have be exhausted, and thats the next option in line then......Why not. mass is mass, sometimes the ease of install is worth the extra money in my opinion.

Once again I apologize for my vague comment on multiple/4layers of deadener.

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Unless your door skins are made from aluminum, you are not going to weld any aluminum bars to it. Soldiering or brazing on the other hand could be feasible, but presents the same problem, repainting the door, as well as distorting the sheet metal.

You may be able to glue or epoxy the bars to the door skin, I don't know what may or may not work, but a quick search will answer your questions.

AS Impious stated (and as I'm doing in my own doors) looking into a sealed enclosure in the door does wonders for rattles created by the back wave of the speakers mounted "in" the door.

I placed 1 8w3 in a sealed enclosure in each door powered by a 500/1 and the mirrors barely move, it's a wonderful thing. Good luck.

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