Fiberglass top repair advice sought

Joined
Mar 6, 2019
Messages
51
Location
earth
I have a 70 FJ40 with damage to the fiberglass top. See attached image. Removing the rain gutter and all the rivets seems unnecessary. I am thinking I can try to remove the rivets for 3-feet either side of the damage. I would then separate the gutter from the fiberglass by no more than about 1-inch. I do not want to forcefully bend anything. I could make a contoured dolly to work the gutter back into shape. I would also have room to repair the fiberglass.

Does my plan sound workable?

toppic.jpg
 
Joined
Oct 30, 2007
Messages
10,416
Location
Plano texas
Hi, Just do it right.If you keep it you will regret it latter. Remember this is a decades ole antique.
 
Joined
Mar 6, 2019
Messages
51
Location
earth
I separated about 1/4 of it. It worked. The old sealant is dust. By putting 2x4 between the metal and fiberglass I had room to work. I was able to get the metal near perfect. I could do the fiberglass easily. But it is actually easier than I thought. The rivets are aluminum. Getting the dried old sealant out of the gutter will be much faster without rivets when I separate the whole thing. As will prepping the metal. I am going to go for it and make it right.
 
Joined
Jan 9, 2020
Messages
484
Location
NorCal
I did this last year. There are a couple of build threads that were helpful. I’ll see if I can find them. Check out pages 3-4 my thread for a few pics of the process.
 
Joined
Jan 9, 2020
Messages
484
Location
NorCal
Here’s one
 
Joined
Mar 6, 2019
Messages
51
Location
earth
Good call to take it apart. The rain gutter is a horror show of rust. It appears that the glue they used was corrosive. The inside surface that was against the rubber is in great shape.
 
Joined
Mar 6, 2019
Messages
51
Location
earth
The fiberglass repair was easy and successful.

The rain gutter is a different thing. The rust in the inside is serious and extensive. I spent several hours removing rust with a little angle grinder with sand paper, wire brushes, and scotchbrite. There are nooks and crannies that will never be clean. Clean is relative, I am not getting to bright clean steel.

Should I use naval jelly or other chemicals?

Will Rustmort stop the rust from progressing further in the inaccessible places?

I could possibly make an electrolytic tank out of a rain gutter. Is it worth the trouble? I would have gone to a laser rust removal service but none are in my area.

A definitive solution would be to by a gutter kit and assemble a new gutter. Any thoughts on that? I would be skeptical of making it exactly like the old gutter as far as bolt lug placement. Yes I would make a jig from the old and transfer the dimensions but it seems like a lot of work. Then again what I am dong is a lot of work and is extremely messy and expensive.

Thoughts?
Thanks ,
Scot
 
Joined
Jan 5, 2017
Messages
4,161
Location
Charlotte, NC & Alexandria, VA
Are new gutters not available? I haven't checked, so I'm asking as much for my curiousity as your situation.

I'd try phosphoric acid solution (like Ospho) before naval jelly. Same active ingredient, but I've found the spray to be easier to work with and less messy. The rain gutter tank idea would work, if you could a) find a gutter that wasn't painted/coated, or b) coat the inside with something non-reactive, like bedliner or POR-15. That's a lot of work for something you'll never use again, though.

As far as getting back to clean, bright metal is concerned, you sound like you have a pretty good mental handle on the problem, so it shouldn't be hard to convince yourself of the obvious: any rust breeds like a pair of rats. If you don't remove it all, well, you're leaving some behind, and then you're eventually back to where you started. If it's thin enough, the acid will convert it to iron phosphate, but you never really know until years later. I'd personally only trust the acid to remove flash rust from a bare surface. And zinc phosphate is better for that, IMHO.

If you can get the gutter pieces separated, glass bead blasting would be an option. Safer than sand, more aggressive than walnut shells.

On second thought, it all sounds like way more trouble than it's worth. PM me your address and I'll take the problem off your hands. ;)
 
Joined
Mar 6, 2019
Messages
51
Location
earth
I was thinking of making a electrolytic tank out of a household plastic rain gutter and using a piece of wire as my anode.

Blasting sheet metal parts has produce banana shaped parts in the past for me.
 
Joined
Jan 5, 2017
Messages
4,161
Location
Charlotte, NC & Alexandria, VA
I was thinking of making a electrolytic tank out of a household plastic rain gutter and using a piece of wire as my anode.

Blasting sheet metal parts has produce banana shaped parts in the past for me.
For sure it can happen. I found that (surprisingly) following the manufacturer's recommendations and using a maximum of 45psi on the bead blasting gun yields markedly better results than the high pressure setting I used for sand.
 
Joined
Jan 6, 2011
Messages
1,235
Location
Salisbury, N.C.
I used my old rain gutter as a template for the new. It made it a perfect match. Measure how it looks if you flipped the old and new face to face. Mark the holes and see if right side up they match. Drill through while still together, screw a bolt through, put a nut on and weld it. Mine worked like that. Both side matched each other.
 
Joined
Mar 14, 2011
Messages
637
Location
Seattle
It really depends on how much of a horror show your gutter is, but I had mine blasted and I patched a lot of super pitted sections. It wasn't terrible, but it was a lot of welding, grinding, and hammer/dolly work. But it all went back together just fine.

I've read that it can be pretty tricky to get those cool cruiser kits put together and aligned well, but I would guess that it can't be any harder than patching. So if I were to do it over again, I'd do what @coinoperated40 did, and use the existing gutter as a template.

Probably the best advice I can give you: Don't buy cool cruiser's rivets. They're too big- the heads are too big to sit flat, and the rivets require to you drill out your top. Instead, get properly sized metric rivets (see the thread posted by @Slapshot above). Also, buy the good two part self leveling seam sealer. It works awesome. And lastly, don't bother with the vice grip tools or rebar and hammer method for bucking the rivets. Just get a cheap air hammer and turn the pressure way down... and find a buck that is domed out to the right diameter. You'll have it riveted in like 30 min, without risking hitting your fiberglass with a hammer. The vice grip tools work okay I think, but they don't buck the rivet into the right domed shape, and I think they're more work than they're worth.

Good luck!
 
Joined
Mar 6, 2019
Messages
51
Location
earth
I watched the videos again. A couple of possible issues came up.

The gutter kit shows the sections have tabs on them. I assume the tabs are for alignment. The vendor told be brazing the sections together was good. I envisioned using the tabs to braze to. My old gutter is flat with no raised tabs. Will leaving the tabs on cause any problems? I would guess they might. I do not own a TIG welder and do not have the skills to but weld sheet metal anyway. I think that grinding clearance in the fiberglass for the tabs may work. Did I mess up by ordering a gutter kit? Should send it back and carefully blast my gutter??

The videos did not mention the coarse fiberglass tape between the fiberglass and gutter. Is it necessary?

The glue for the fiberglass to gutter? They wanted to sell me 3M 08505. That is fast setting stuff. I planned to glue the fiberglass to the gutter. My fiberglass was cut small by the factory. ON one side the rivet holes are very near the edge of the fiberglass and there is a large gap to fill n the gutter. I do not feel the relying on rivets alone is enough for strength. The 08505 will dry before I can set all the rivets. I think that 3M 5200 may be a better product. I used it once long ago, I do not remember if it was runny or like peanut butter.

Regarding the gap... It appears that Toyota used some kind of glue to repair the poor cutting of the fiberglass . A lot of it chipped off. I could make a repair to extend it back out. I was thinking of using fiberglass reinforced bondo. I would also use G-flex epoxy and fiberglass cloth. That would make it a bit ticker though. Thoughts?

DSCN0408.JPG
 
Last edited:
Joined
Jan 6, 2011
Messages
1,235
Location
Salisbury, N.C.
I restored my top long before I knew about this forum. I became friends with a backyard body shop person and together over the course of FIVE years, we removed and replaced almost everything. When it came to the top, his thought was to add something like a body seam roll of a black roll between the fiberglass and the rail. It is paintable and still a little flexible. Like everyone else’s top, you could see how the water had found its way between the glass and metal. My replacement metal did not have any tabs and was just as if you had cut the old metal into pieces.
Do you have a boat shop in the area to maybe ask about the fiberglass. It doesn’t look to serious.
It sounds like most people attack the sealing problem from the top with the self leveling sealer. It does take time to install all the rivets, so not sure anything fast drying would work.
 
Joined
Jan 5, 2017
Messages
4,161
Location
Charlotte, NC & Alexandria, VA
^^This. Lots of anecdotal experience here with Sikaflex. Everyone who has used it loved it.

The top is just fiberglass; not NASA grade stuff. Treat it the way you would treat a boat.
 

Users who are viewing this thread

Top Bottom