Hood bracing

[70barracuda]

So my hood bracing has separated from the skin, assume it was part of my accident. I'd really like to keep this hood. Seems like it was an epoxy they used to secure it. Anyone have recommendations for some strong stuff? 

[Comanche SS]

6 minutes ago, 70barracuda said:

So my hood bracing has separated from the skin, assume it was part of my accident. I'd really like to keep this hood. Seems like it was an epoxy they used to secure it. Anyone have recommendations for some strong stuff? 

I always thought it was panel bond…similar to what they used on the firewall, floor, inner fenders braces etc.


I could be vastly wrong though. 

[89 MJ]

I would use panel bond as well. I’d guess the factory used something different, but panel bond would probably be better. 

[70barracuda]

Alright thanks guys. I'll pick some up and give it a shot

[ghetdjc320]

You could spot weld & panel bond the perimeter but the actual internal bracing had a foam layer between it and the hood skin. You can use a flexible 3m 2 part foam if you want to recreate the original. 

[AZJeff]

There are structural adhesives used in the body shop industry that will bond your hood pieces in the center areas quite nicely, and will be mush more effective than the stuff AMC and Chrysler used back when MJs were in production.

 

if you know of a body shop supply store, they would carry this type of stuff.  Otherwise, some internet searching is you next best bet.

[ghetdjc320]

Oreillys carries all the 3m panel bond adhesives around here. What they don’t have in stock they can get in a day or two. I don’t think panel bonding to the frame structure in the center is called for here though. I’m guessing there is some reason why they used a pillar foam in place of an adhesive. It would have been easier just to tack weld it in a few spots. Wonder if maybe heat transfer or crash crumpling zones are part of the equation 

[AZJeff]

1 hour ago, ghetdjc320 said:

Oreillys carries all the 3m panel bond adhesives around here. What they don’t have in stock they can get in a day or two. I don’t think panel bonding to the frame structure in the center is called for here though. I’m guessing there is some reason why they used a pillar foam in place of an adhesive. It would have been easier just to tack weld it in a few spots. Wonder if maybe heat transfer or crash crumpling zones are part of the equation 

Any welding in the middle of the hood to attach the under structure to the hood skin is going to distort the surface at least minorly, and that would necessitate some secondary work to remove that distortion.

 

Adhesives of any kind will keep the surface skin from “oil canning” against the underlying ribs and making noise.

[ghetdjc320]

8 hours ago, AZJeff said:

Any welding in the middle of the hood to attach the under structure to the hood skin is going to distort the surface at least minorly, and that would necessitate some secondary work to remove that distortion.

 

Adhesives of any kind will keep the surface skin from “oil canning” against the underlying ribs and making noise.

Agreed. It’s probably similar to the method used on the tailgate panels. On all the hoods I’ve seen, there is a decent gap between the inner frame and the skin in some areas. Panel bond adhesives could not take up such large gaps. 

[70barracuda]

I'm gonna try the adhesive first, but if it comes to it I'll just tack weld. Not like I really care about the paint haha

[pizzaman09]

I work for a company that makes panel bonding adhesives that OEMs use.  In this application I'd probably use a urethane based adhesive.  Make sure you choose an adhesive with a decent working time, there is a wide range from 30 seconds to 15+ minutes.