TheSamba.com :: View topic - Suggestions on repair of fiberglass fender bolt holes

Wed Jan 01, 2020 5:19 pm

So this isn't the first time I've seen this or had to deal with this, but its the first time I've cared.

I'm finally getting into the baja that has literally been taking up garage space for the last 7 years. Old and I mean OLD school socal bug eye kit was put on this baja and I now want to preserve it.

My question and trouble area is he bolt holes in the fiberglass. The PO or someone along the line ripped them out with the bolt still in place. Then glued it back to the body with the remaining bolts in place.

Since this is an old kit there is absolutely no reinforcement near the bolt holes just old fiberglass. Now I have thought about and could glass in space on the bottom to "complete the hole" and make it look decent again. But the glass will always be weak and I'm not gonna get after it hard with this one or be in the dunes but its also not a "patina trailer queen".

Only other thing I can think of is maybe washers glassed into the tab but even that will make offset.

Wed Jan 01, 2020 6:52 pm

Pics are worth a thousand words. Dzus fasteners?

Wed Jan 01, 2020 7:18 pm

I know and sadly I'm at work and not home for a couple days. I have a few of those at home and tried to mock up but mine are like 3/4 of an inch and I would say at most the lip on the fenders is 7/8 to an inch, at most.

Wed Jan 01, 2020 7:28 pm

surfer510 wrote: Only other thing I can think of is maybe washers glassed into the tab but even that will make offset.

First always pictures.

This but more. Instead of washers a strip of aluminum shaped kind of like the fender gasket. Maybe strips split into pairs of holes - a "long washer". glass that into the fender to strengthen it.

Wed Jan 01, 2020 7:41 pm

L5wolvesf wrote: surfer510 wrote: Only other thing I can think of is maybe washers glassed into the tab but even that will make offset.

First always pictures.

This but more. Instead of washers a strip of aluminum shaped kind of like the fender gasket. Maybe strips split into pairs of holes - a "long washer". glass that into the fender to strengthen it.

Thanks I hadn't thought about the long washers and cheat it to the inside of the fender.

Also I will get pics as soon as I'm home. Just sitting here working out my to do list when I get home and this is my most pressing WTF moment that I've been having. I love the kit and love this baja as its just old school but preserving the old school has become a major PITA

Wed Jan 01, 2020 8:32 pm

I am going to be repairing a Dune buggy body that the flange that mounts the body to the pan is tore up, I am going to cut a stripe of 1/4" plywood and glass that to the body with unidirectional fabric and bolt through the plywood and glass with big fender washers. maybe you could do the same inside the fender.

Casey

Wed Jan 01, 2020 8:52 pm

Typical repairs would be to grind away old oxidized or cracked material and find virgin base material, mix up resin and hardener and build up area with mat or glass cloth... It's usually the typical way to repair fiberglass issues.... Have done three complete dune buggy bodies back to like it came from out of mold and because idiots (previous owners) cut, cracked, broke and generally made a mess of bodies....

Look up procedure for corvette or boat hull repairs, pretty much same principles...

Both of these bodies were restored to like they came out of mold so I could perfect the build without having to use previous damage as part of my build...

Dale

Thu Jan 02, 2020 8:53 am

Back when I used to tear up boats on a regular basis, we repaired fiberglass with wire mesh and new fiberglass. Grind away the shredded material from the back side of the damaged area but not all of the way thru. That way, you're removing the shredded stuff but keeping the shape. Lay a section of 1/4 inch wire mesh over the area and push mold it to fit flat. It has to be flat against the fiberglass. I used clamps and weights to hold it in place while I glued it in place with small globs of "resin snot". Thicken up a small amount of resin with cut strands of fiberglass mat to make "resin snot". I think you can buy stuff like that ready made too.

Once the metal mesh is glued down and firm, layer on the glass'. Generally speaking, the matt is stronger than the cloth because the fiberglass strands go in all directions. It also molds to uneven surfaces better. Work it down into the wire mesh so it fills the openings. You can layer on extra layers of wire mesh if you need them. Glass' on one section, then add another and glass' that one in place, etc. Metal mesh-fiberglass-metal mesh-fiberglass, etc. etc. If you decide to use multiple layers of mesh and glass', make the next layer of wire mesh smaller than the one under it. That will allow some flexibility and spread the load.

To make edges, I just let the wire mesh stick out, then cut it off after it was all cured. The idea is that the new fiberglass bonds to the underlying layer of glass' thru the metal mesh, like Rebar in concrete.

Thu Jan 02, 2020 10:10 am

i started doing fiberglass repair at big truck body shop a little over 20 yrs ago and these guys are right, first you gotta know how to or research how to repair fiberglass properly . othern that id just add that youll have to glass the whole area around the hole then redrill a new hole. and its been my experience for reinforcing glass, wood is good because it will absorb the resin and bond together with everything. for what your doing paint stir stick pieces are a perfect thickness

Thu Jan 02, 2020 12:37 pm

Thanks I appreciate all of your help and advice, I have glassed before and know the general ways of repair (in no way am I an expert). My biggest concern is the stability of the fender after the repair.

This is from what I've been told is a very original 60's baja kit, the actual fender is super robust and strong still. The "lip" that bolts to the body is weak old and as i mentioned was literally at some point i think ripped from the car with the bolts still in it.

I could glass the lip in and re-drill the holes but I'm worried about the support of the new glass going to the old glass and how to tie both in effectively.

Thu Jan 02, 2020 2:42 pm

surfer510 wrote: Thanks I appreciate all of your help and advice, I have glassed before and know the general ways of repair (in no way am I an expert). My biggest concern is the stability of the fender after the repair.

This is from what I've been told is a very original 60's baja kit, the actual fender is super robust and strong still. The "lip" that bolts to the body is weak old and as i mentioned was literally at some point i think ripped from the car with the bolts still in it.

I could glass the lip in and re-drill the holes but I'm worried about the support of the new glass going to the old glass and how to tie both in effectively.

IF you grind down into old glass enough to find solid material its all you need to do.... You can build any amount of new material you need to get form right, do not be afraid to work both sides of fender flange, you can build out wheel side of grande with a large overlap of material and strength flange quite well, then you can grind, sand and whatever to work it to exact fit....

Dale

Tue Jan 07, 2020 3:17 pm

BTW...In the 60s, and only in the LATE 60s, fiberglass Baja Kits were ONLY made by the original Miller-Havens. In the early 70s, the market in SoCal was flooded with people making fiberglass Baja kits. I have some old bug-eye kits here. Little to NO difference between my old Baja kits and brand new Mark 5/EMPI from my early 70s stuff. Once upon a time, I could recognize a Miller Havens Baja kit from the imitators, but not anymore. There HAVE been some hand-laid fiberglass Baja kits that were very nice. But in working on more exotic race cars, I've found myself working with $3K each fiberglass fenders on a Porsche that were no better than the $60 for a whole Baja kit fiberglass that I bought in Tijuana in 1973 (with high-back seats thrown in).

My point is that it's HIGHLY unlikely that the fiberglass parts on your Baja are anything special. Unless they're hand laid cloth, they aren't any different from a pair that sell on the classifieds here for $30 a pair. Get over the seller's BS and just repair them.

I'll see if I have any pictures of the repairs I did to one of my fenders after someone backed into it and tore off a hand sized chunk in a gas station. Nobody can tell now even when I point it out to them. I'm sure someone who knows about repairing fiberglass could find the repair, but so far in the last 12 years, nobody HAS. I'm telling you this not to brag on my repair skills... I'm not selling my services anymore, I'm retired... but to convince you that you do NOT need to worry about fixing the fiberglass yourself. If you do as suggested above, ESPECIALLY the part about prepping the surface where you're going to repair down to solid original material, then your fix should be as good as new.

Then, know that rear fenders could use a little support from underneath to prevent future cracking. And some cheap fenders over the years have had some very slim flanges that could use some additional fiberglass underneath to make the flange larger.

The long washer idea is a fine one too.

Thu Jan 23, 2020 6:15 pm

Dustymojave thanks for the response I was actually thinking of DM'ing you, love your input and experience. I was also thinking that the PO was full of shit. I do love the old girl though and do want to keep her as OG as possible on the outside. Everything else will be new.

Also thanks everyone else that has taken the time to respond back love this resource and the baja/sand community.

Fri Jan 24, 2020 3:53 pm

I have seen fenders widened by cutting 1" plywood the same shape as the flange and resined on and glass laid over the top and bottom and the new holes drilled through the plywood and the old flange, gives you a extra inch of clearance for tires.

Casey

Fri Jan 24, 2020 7:02 pm

Here are those pics of the repair to my right rear Baja fender in 2008. Somebody had backed into my fender at a gas station. I picked up the hand sized piece broken out of the lower edge of the fender.

To repair it, I clamped a piece of plastic cut from a plastic detergent jug to the fender with 'C' vise-grips to make a smooth surface on the outside of the fender. Then I cut the pieces of glass cloth for the repair. I used 4 layers of cloth. Then I mixed some resin and applied a little to the edges of the break. Put the broken piece in place and applied the resin and cloth with a disposable paint brush. After the 4 layers were in place and all bubbles removed from the resin, I let it set for 1/2 hour. Then I removed the piece of plastic (the polyethylene does not stick to the resin). The fender already looked pretty good. I applied a thin layer of glass reinforced Bondo. Another 15 minutes and I sanded the bondo by hand with a sanding sponge. A few minutes of that and it was ready for primer.

Try to spot the repair from the outside.

Not all that easy to spot from underneath either

More obvious from up close

Cost less than $20 and took less than 1/2 day including waiting for the resin and bondo to set. Actual labor time probably less than 1/2 hour.