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73 Heater Box Cracked
#1
After reading all the great advice on how to remove my 73 heater /AC box on the forum, I got it out without a lot of surprises. I put the box on my work bench and knocked it off where it dropped to the concrete floor and cracked. The crack is very clean and if I push it together I can hardly see it.

Any idea how to repair the crack? Other than the new crack the box is in great shape.

The internet says to clamp the crack, grind a small V in the crack and fill with resin. But I am not sure if that will hold up, I have no experience with fiberglass. Any help is greatly appreciated. I would be up for buying one if anyone had one in decent shape.
       

Sorry about the upside down pics, they are upright in my file.
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#2
fiberglass repair kit, Sand the area of repair, then Clean it REALLY well, mix up the resin and cut the cloth to the area, Butter the repair area with the resin, apply the mesh, then coat with resin, push together the repair as needed, use vice etc.. then adjust the mesh smooth, let dry, sand if needed.

you can cut a V if you want also.
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#3
Ok, that sounds like something I can do, I thought I would need a patch. Thanks for the advice.
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#4
I have found that fiberglass tends to release from the material these heater boxes are made of.. I use JB Weld Epoxy. Clean the area very well with 90 percent denatured alcohol inside and out and let it dry. This is critical because when these parts were molded, they used a silicone mold release agent, which tended to penetrate the material.. After cleaning, lightly sand each side of the crack, inside and out, 1 to 1 1/2 inches out on either side of the crack. No v-grove needed.. Mix the JB Weld per instructions and lather into the crack and clamp it together immediately.. The epoxy only gives you a few short minutes before it cures. I use a small woodworkers slide clamp you can get from Harbor Freight.. Let it cure and keep it clamped... Now, lather JB weld out on each side of the crack and overlay the seam with more of the epoxy.. Let it cure.. Repeat lathering it on the inside.. Build it enough to achieve a solid bond and sand it back for looks..

The person who says it cannot be done should not interrupt the person doing it. 
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#5
I fix these all the time. I use a product called"Plastix" available from Eastwood. The black kit allows for almost an undetectable repair. It is an Acrylic powder.
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#6
.....
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#7
I thought about JB weld first, I have used it for many years. Its messy but with the right amount of sanding it may work. My experience with JB weld is on hard smooth surfaces it tends to release, I know the housing is much different at it may work well, again I have no expedience with fiberglass.

Piper, that is an interesting note about the silicon mold process. Do you think a fiberglass patch will release even if I sand the area real well and clean it as you and 72Hcode are saying?

Judge, I dont see that product at Eastwood, and a google search didn't return anything. Do you have a link?

This car was restored back in 1995 ish and is still in excellent shape, I would like to replace the housing first then try the repair if I cant find a bottom cover in good shape to purchase.
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#8
you know another option if you just don't want to deal with it as a repair; they make a reproduction heater box now
http://www.cjponyparts.com/heater-box-as...73/p/HBA6/
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#9
Thanks 72Hcode, I see the new ones but I'm trying to avoid spending those kind of dollars and if I can keep OEM I am always happier with OEM. Ebay has a real nice original one at $400, I would buy that first. I'm in no rush, the car is in storage until the end of March. Either I fix it or Ill find a used one. I cant believe the self inflicted trouble I caused.
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#10
[quote=Pastel Blue;290140]
+1 for jb weld.
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