Inner Heater Box Fiberglass Repair Suggestions

[Michael A.]

I have the inner heater box out of my 66 SB Roadster and am prepping it for re-installation. Unfortunately it has a pretty big crack in it. The pictures show it separated but it can be easily matched up pretty cleanly for gluing. Does anyone have suggestions on how best to repair it? My thought is to put a flat piece of material on the inside of the box, gluing it to the inner wall. Is that a good plan? Any suggestions on what I should use as a backing material an glue?

I really appreciate suggestions. Thanks.

[Bob R.]

Re: Inner Heater Box Fiberglass Repair Suggestions

Mike,
You can buy fiberglass cloth and resin at your local Home Depot. Scuff it up a bit so you get a good bond and lay a couple of layers of material on the inside surface.

[Harry S.]

Re: Inner Heater Box Fiberglass Repair Suggestions

It does take time and patience but it is fixable.

[Joe R.]

Re: Inner Heater Box Fiberglass Repair Suggestions

Wow Harry! Impressive! Keep it up and you'll turn into another Mottszerella! Pictures and all!

Looks like fiberglass around the edge and something like JB Weld over the patch. Maybe you would want to do the patch for Michael!!!!

Small business you know!

JR

[Harry S.]

Re: Inner Heater Box Fiberglass Repair Suggestions

I used some thin fiberglass cloth and resin, no JB weld used. Then lots of sanding.

[Gene M.]

Re: Inner Heater Box Fiberglass Repair Suggestions

I used some thin fiberglass cloth and resin, no JB weld used. Then lots of sanding.

Harry,
Scott has performed some remarkable repairs on tire tubs and lid of the same dark fiberglass that are almost undetectable. I have not seen anything detailing the process he does but I suspect he does have one. I have done smaller repairs on dark glass that I was satisfied with but were not undetectable by me.

[Richard M.]

Re: Inner Heater Box Fiberglass Repair Suggestions

It does take time and patience but it is fixable.

Harry, Nicely done! You do nice work!

Wow Harry! Impressive! Keep it up and you'll turn into another Mottszerella! Pictures and all!

Looks like fiberglass around the edge and something like JB Weld over the patch. Maybe you would want to do the patch for Michael!!!!

Small business you know!

JR

LOL....That's what my French Canadian Mother-in-Law used to call me since I met her daughter at 17 and for years after I married her...Richie Mozzarella.

Do you know her?

[Michael A.]

Re: Inner Heater Box Fiberglass Repair Suggestions

It does take time and patience but it is fixable.

Wow Harry! That's very well done. It looks like you removed the riveted steel backing plate, is that correct? How was it to re-install the rivets? I've not done that before.

My crack is at the other end of the box near the mechanism that controls the heater/defroster damper. My first thought was to try and repair it without removing that mechanism. It still works and the cracked pieces mate up very well. Am I asking for trouble?

Also, are the pics you attached showing the fiberglass cloth and resin method that Bob is suggesting above?

Thanks for the great reply and excellent pics.

[Harry S.]

Re: Inner Heater Box Fiberglass Repair Suggestions

Wow Harry! That's very well done. It looks like you removed the riveted steel backing plate, is that correct? How was it to re-install the rivets? I've not done that before.

My crack is at the other end of the box near the mechanism that controls the heater/defroster damper. My first thought was to try and repair it without removing that mechanism. It still works and the cracked pieces mate up very well. Am I asking for trouble?

Also, are the pics you attached showing the fiberglass cloth and resin method that Bob is suggesting above?

Thanks for the great reply and excellent pics.

I took every rivet out of the box and completely disassembled the box. Media blasted all the metal pieces then primed and painted them with stainless steel paint. I used a seal and rivet kit from Dr. Rebuild. It does take two people to install the new rivets due to their location.

Good luck

[Michael A.]

Re: Inner Heater Box Fiberglass Repair Suggestions

I took every rivet out of the box and completely disassembled the box. Media blasted all the metal pieces then primed and painted them with stainless steel paint. I used a seal and rivet kit from Dr. Rebuild. It does take two people to install the new rivets due to their location.

Good luck

Thanks Harry. I've not decided yet if I will take it down as far as you did. My hesitation is the rivets and the damper mechanism. All is working well with the mechanism so I'm hesitant to risk messing that up.

As for the rivets, I've never done them before. Removal should be simple by just drilling them out. For the replacement, what kind of rivet tool did you use? Why did it require two people?

Thanks again Harry. You're an example of why I love the TDB. There's no substitute for someone who has done it before and has the pics!

[Harry S.]

Re: Inner Heater Box Fiberglass Repair Suggestions

Thanks Harry. I've not decided yet if I will take it down as far as you did. My hesitation is the rivets and the damper mechanism. All is working well with the mechanism so I'm hesitant to risk messing that up.

As for the rivets, I've never done them before. Removal should be simple by just drilling them out. For the replacement, what kind of rivet tool did you use? It was a small rivet set and a small hammer. The rivets are soft aluminum.


Why did it require two people? The box needs to be balanced on a bucking board or anvil to set the rivets

Thanks again Harry. You're an example of why I love the TDB. There's no substitute for someone who has done it before and has the pics!

See Answers in BOLD above

[Ron L.]

Re: Inner Heater Box Fiberglass Repair Suggestions

Harry - I have a 64 - no A/C. lt has been so long ago since I tore the box apart, I am trying to determine what is the purpose of the two longer rivets/screws I see in the picture which go through those humps. Any recollection?

[Harry S.]

Re: Inner Heater Box Fiberglass Repair Suggestions

Harry - I have a 64 - no A/C. lt has been so long ago since I tore the box apart, I am trying to determine what is the purpose of the two longer rivets/screws I see in the picture which go through those humps. Any recollection?

They attach the mechanism to the top of the box that the cables attach to.

[Ron L.]

Re: Inner Heater Box Fiberglass Repair Suggestions

My controls are still attached to the fiberglass box, and I have removed the metal plenum piece. Again, the holes to which I refer are larger than the rivet holes and are the ones in your picture which are larger and longer than the rivets. Were there cable clips through which a cables was fed before it got to the control?

[Richard M.]

Re: Inner Heater Box Fiberglass Repair Suggestions

Ron I think Harry is down in Florida at the Regional, but until he checks in I did a little homework. Here's a reference photo of the box and the mechanism/bracket. Those are screws to mount and adjust the mechanism.

1963HeaterBox_mag1.jpg
Here's a 1967 box I restored, and you can see the cable mount flange on the left.
P7250015.jpg