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Fibreglass repair

mojobaby

mojobaby

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3 years ago I had a huge hole in the floor of my car. It was initially caused by rust but my heel rested on that spot and the hole just got bigger and bigger.

Before anyone jumps down my throat and tells me that I should have welded a new panel, let me explain

I've only just taught myself to weld, but thin metal is still a problem.
A quotation I received from a pro welder was too expensive.
I'm not sure, but I think a floorpan replacement means a "body off" operation and I don't really want to go that route at this time.
I have repaired my surfboards many times so I know how to work with fibreglass.

So please watch the video and let me know your thoughts. Both positive and negative comments are welcome.
some day I hope to do the job the right way:)

 
No :doh:
Don't :doh:
Do:doh:
It :doh:

Now that I have your attention!

Water in the form leakage from the front windshield, condensation, or your boots will enter from the inside. Will rubber mats or sodden carpet sit on your repair?
Splash from the road will be forced forced into your repair from every direction.
Wherever the water comes from it will not escape.
A rust problem that took 30 years to develop and that you think has been fixed will take 2 years to reappear.
If it's for a dodgy fix before a sale then it's for your conscience.
If it's a keeper then you have to do it properly.
I didn't have the skills to weld. I fibreglassed.
 
How ingenious

Well done a great job using simple tools and equipment.

Cheers

Ian
 
Perfectly fine IMO. That patch will probably be stronger than the rest of the floor pan too. David, Why do you think it will soon fail. GRP cars don't have a history of leaking floors. On my car, the hole for the former roof aerial has corroded to about 2" diameter, and that is how I shall repair it too. He could also have considered pop riveting a sheet of thin stainless steel over the hole.
 
Hi David M, I had the same concerns as you. thats why I did the anti-rust treatment twice.

I also fibreglassed from underneath the car and then used that black underbody sealant. Water will never get through.

I have a rubber mat, the usual one that we all have, and I also have a second rubber mat on top that collects any mud or sand. The damage to the floor was initially caused by a brake fluid leak and then I presume that water came in from under the car

I think I mentioned that the repair was done 3 years ago and there's no sign of rust recurring. So I'm quite happy with the way the repair has lasted.
I take your point that if its a "keeper" then do the job the correct way.

Paul, I was a little worried that my heel would wear through even though the patch is really strong. So yes, I have a thin metal piece over the patch but its not pop riveted.
 
I am strongly against GRP repairs like that. But I am liberal minded and enjoy your posts.

There is a modern philosophy that says you can keep water out of things completely and forever by splashing coverings on every now and then. Modern house design (in the UK) is based on that principle so it can't be wrong. My house was painted in waterproof paint and the walls became very wet because the water couldn't escape past the waterproof paint. Seems to me water will always get in. Trick is to allow it a path out again. I have always followed the same philosophy on cars.

I reckon any double skinning is a bad idea whatever the second skin is made of - second sheet of metal, thick underseal, fibreglass.... Water will get in and won't be able to escape. Water does that whatever you do - if you unpick the repair after a few years you will find it wet and festering in there.

A brilliant welder for thin metal with all the gear will be very much cheaper than a nice bicycle. But a welder won't make you fit. Forget the car - buy the bicycle!
 
I was following, although not necessarily agreeing with that until the last paragraph. Then your views became, err, wonky.
 
Nice fibreglass repair ! I guess, though, that many of the above comments about festering moisture allowing rust to march on may well be true - eventually! An imperfect welding and de-rusting repair job will have the same problems as well though. There can be issues with relative expansion/contraction cracking the (GRP/metal) joint area, with flexing doing the same of course. Pro body shops remove the rust by cutting the whole area out - for a good reason.

Welding: thin metal welding is a pain but is achievable with a little practice, with 0.6mm MiG wire and low power. Practice! Some MiG welder machines are better at this than others; sometimes the key is a very short higher-power burst (practically a spot) then a brief rest. Repeat; the weld should end up fairly flat. It may seem a slow way to do it, but in the end it is efficient as it provides good penetration, little buckling and not so much grinding-off bird-poo lumps of poorly-penetrating weld. Easier said than done in awkward places though. Clean the metal to a silver finish every time or it just won't work right. Welding on top of 'Kurust' is a challenge as well, though 'POR15 Metal Prep' rust chemical treatment seems OK for that. They each leave different metal deposits after reacting with the rust.

Long weld runs generally are difficult with thin (ie Renault) metal, as the temperature of the metal panel increases rapidly with welding time, leading to melted holes and the heat can buckle the metal badly too. Thicker metal soaks the heat up and it won't buckle so easily.
Clarke MiG welders are good for home use - I use one. An SIP MiG I also have needed modification to the wire-feed bracketry and a separate wire-feed power supply to make is useable at all; stick to Clarke! Anything up to 5mm thick with some chamfering of edges using 0.8mm wire is weldable with a household-sized MiG welder. I rarely use the lowest power setting, as the above 'spot' method a power setting higher seems to work better with biscuit-tin thicknesses.

I have a jolly habit of buying clapped-out rusted wrecks no matter what I set out to buy; the van I have was 'restored' a year or two previous to my buying it - I have since welded the cracked window-frame corners (filler removed), rear door corners (filler removed), chassis, inner front wings and rear door strap areas (they didn't even bother painting that bit). They fitted a new timing chain without realising that the chain tensioner was siezed, a new clutch without crank or cam oil seals.... there are monkeys everywhere.
 
Adam Hi! your mention of buying a restored van got me thinking if there's a slight "defect" in your English :whistle: as in my book Restored
usually means just that..it's been stored in a derilict shed for yonkers when this finally caved in the van was dragged to the next shed
ie; REstored. -Reid.
 
Adam+Malcolm, I have a Mig welder by Far Tools. I have drills, sanders, grinders etc by the same company and I'm quite happy with their quality. Not sure but I presume they're all from China land.
I have a spool of 8mm wire and I know for thinner metal I should have 6mm. I've also never tried it with gas which I think is necessary for thin metal.

But like all things, I just need to practice a bit more:)
 
hi mojobaby - yes, gas (argon 5% with CO2 perhaps) is necessary for all MiG welding, unless you use flux-cored wire which I have never tried but doesn't sound as good from what I have read. If you buy some gas (and 0.6mm wire), the welding ability that you have may be a relevation.
You know what they say about a hammer - when you have one, everything looks like a nail? Same thing for a MiG welder nicely set up - when you have one, everything is weldable!
No doubt most gear is made in China, and some of it is very nice - but I think it's a bit of a gamble somtimes. Glad you are happy with your machine :)
 
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