2004 ultra glide. what is the rear trunk made of? fiberglass?

 

Don't believe that is fiberglass. I repaired mine with a 2 part epoxy and it's been 8 years and no issues.

 

They used to be, mine is,don’t know when they transitioned to abs.

 

If the inside is white its fiberglass, which i think that year was can't remember when they switched to plastic, which will be black

 

Ok. My research says up to 05 the touring pack is made of fiberglass. 06 and newer are ABS plastic. So I am going to try and fix it with some boat yard polyester resin and fiberglass cloth. I am thinking i should not have installed the luggage rack on it. to much stress i think?

 

You need to use epoxy resin and not polyester resin, otherwise, you will have delamination issues down the road. The tour-pack isn't conventional fibre glass construction, but rather SMC (sheet molded compound). A good work around , is to create a backing panel using fiberglass/ polyester resin and laminating it to the repair area using an epoxy adhesive. I repair commercial transport hoods using a similar technique. Hope this helps.

 

I'm pretty sure H-D is not using ABS. I think H-D calls the material GTX, which is a nylon composite.

Someone can chime in, but members here have had positive results using JB Weld.

BTW, welcome and nice ride!