Discussion
Hi,
Earlier in the year I noticed a few small bubbles in the paintwork of my Taimar which I thought might be down to a previous owner having had the car sprayed when it was damp but in the last couple of months it has now got bad and there are bubbles everywhere.
Went in to my local spray shop to a guy I have know for years with a view to having a respray, he had a look and is sure that it is not the paint but osmosis in the fibreglass.
It is only on the main body and doors, not on the bonnet or tailgate.
Anyone had the same problem and if so what was the cure.
Grant
Earlier in the year I noticed a few small bubbles in the paintwork of my Taimar which I thought might be down to a previous owner having had the car sprayed when it was damp but in the last couple of months it has now got bad and there are bubbles everywhere.
Went in to my local spray shop to a guy I have know for years with a view to having a respray, he had a look and is sure that it is not the paint but osmosis in the fibreglass.
It is only on the main body and doors, not on the bonnet or tailgate.
Anyone had the same problem and if so what was the cure.
Grant
Try this ...in production the air lines in the 70's did not have water traps, so when the base primers were sprayed on whilst the basic shell was being prepared the water got onto the surface of the gel coat and what you are now seeing is frost damage......where the water is expanding and turning into ice and lifting the paint into bubbles, this water is reacting with the gel-coat and you now need to go back to gel-coat and repaint from zero and do not use any water until in any of the processes until the topcoat is ready to be nibbed back and polished.
Adrian@
Its likley that the bonnet has been replaced and if this is a 77/78 car then the hatch re-done to perhaps fill in hatch vents.
Adrian@
Its likley that the bonnet has been replaced and if this is a 77/78 car then the hatch re-done to perhaps fill in hatch vents.
Edited by adrian@ on Monday 4th December 13:46
adrian@ said:
Try this ...in production the air lines in the 70's did not have water traps, so when the base primers were sprayed on whilst the basic shell was being prepared the water got onto the surface of the gel coat and what you are now seeing is frost damage......where the water is expanding and turning into ice and lifting the paint into bubbles, this water is reacting with the gel-coat and you now need to go back to gel-coat and repaint from zero and do not use any water until in any of the processes until the topcoat is ready to be nibbed back and polished.
Adrian@
Adrian@
Thanks Adrian, I am taking the car back to them soon to have the worst part of paintwork on the roof cut back to see what is happening, I will let them know what you say.
Cheers Grant
I think what you will find is ... a water filled indentation where the paint has tried to hold the water in place (once you have broken open the top paint surface). THE ONLY repair is to take all the paint off with a orbital grinder and re-define the panel after using a primer sealer filler (I know what we use but I would ask the advice of Trevor Bee at TET mouldings and post back to us with a generic product that he uses when producing body panels) then a guide coat prior to painting (I will not use body fillers though many do ...we use gel-coat mixed with the sieved dust from the extractor system at the fibre glass producers to make a fibre glass filler so that it does not shrink) NOT until the top coat is finished do we get water anywhere near the car. Adrian@
Hi Colin, I had not heard that one ,but the method of inserting the metal hoop into the hatch was perhaps hi-tech enough for it to be deemed a toublesome item for the production staff to deal with.
Hi Colin, I had not heard that one ,but the method of inserting the metal hoop into the hatch was perhaps hi-tech enough for it to be deemed a toublesome item for the production staff to deal with.
Edited by adrian@ on Monday 4th December 14:32
My experience in this is the following:
I had a Grantura with the same spots all over the car.
I sanded it off till bare glasfibre, than I kept the body dry in a heated garage for about two monhts and after that I did crack repairs , primer respray and colour respray.
Now, 15 years later, the car still looks nice and smooth. Not ONE spot came back.
I had a Grantura with the same spots all over the car.
I sanded it off till bare glasfibre, than I kept the body dry in a heated garage for about two monhts and after that I did crack repairs , primer respray and colour respray.
Now, 15 years later, the car still looks nice and smooth. Not ONE spot came back.
I agree with cantus.
Over a period of years a fibreglass body will deteriorate and become affected by a phenomenon called osmosis. basically as the body ages and flexes and gets stressed / knocked / left out in the rain etc etc. Moisture can enter the fibreglass fibres when they become exposed.
The process for treating boat hulls is the same, When you anti-foul a boat hull you must lift the hull from the water and only treat once the moisture content of the hull has reduced to a specific recommended level.
Although not a boat hull, the body of a TVR will suffer in exactly the same way over time. basically the body is ageing and becomming brittle.
The only way to rectify is to ensure the body is stored dry and every opportunity given for the fibres to dry out. You can then repair in the time honoured fasion but ensuring you only work dry.
Ultimately if you only have a small area affected then you can repair the localised area.
I would be very surprised that residual moisture vapour from air lines during production would cause your problems 15 - 20 years after introduced.
Neil.
PS. My old shell for my dad's vixen has sat in a Bolton back garden for 15 years. Now that will definitely need dried out before work can begin??
Over a period of years a fibreglass body will deteriorate and become affected by a phenomenon called osmosis. basically as the body ages and flexes and gets stressed / knocked / left out in the rain etc etc. Moisture can enter the fibreglass fibres when they become exposed.
The process for treating boat hulls is the same, When you anti-foul a boat hull you must lift the hull from the water and only treat once the moisture content of the hull has reduced to a specific recommended level.
Although not a boat hull, the body of a TVR will suffer in exactly the same way over time. basically the body is ageing and becomming brittle.
The only way to rectify is to ensure the body is stored dry and every opportunity given for the fibres to dry out. You can then repair in the time honoured fasion but ensuring you only work dry.
Ultimately if you only have a small area affected then you can repair the localised area.
I would be very surprised that residual moisture vapour from air lines during production would cause your problems 15 - 20 years after introduced.
Neil.
PS. My old shell for my dad's vixen has sat in a Bolton back garden for 15 years. Now that will definitely need dried out before work can begin??
Hi Neil..all
I can only conclude over the last 30 years that this is what has happened to 4 or 5 of my own 51 TVR's (one of them being a 3 year old 1600M) and lots of customers cars, I've run this past them asking when did they first notice the problem, they too had purchased near perfect low mileage cars, that had never seen a frost, then on the first time that they have been exposed to frost the wings and roof tops have had then become spotted, and if left in a severe frost the complete panel has done the same. My thoughts are that the panels were perhaps painted almost as soon as the being made and too quickly (then there might be a solvent issue) the gel-coat should of stopped any end strands being exposed (absorbtion into the end strand issues that you see around poor repairs) but that taking the panel back to the surface gel-coat and re-starting the paint process in paintshops water free cures the problem (given that I have never hurried cars that are having re-paints through the paintshop and enforce a no water process then therefore perhaps by luck more than judgement end up being dry for several months). Adrian@
Neil .....post me direct with you address etc.
I can only conclude over the last 30 years that this is what has happened to 4 or 5 of my own 51 TVR's (one of them being a 3 year old 1600M) and lots of customers cars, I've run this past them asking when did they first notice the problem, they too had purchased near perfect low mileage cars, that had never seen a frost, then on the first time that they have been exposed to frost the wings and roof tops have had then become spotted, and if left in a severe frost the complete panel has done the same. My thoughts are that the panels were perhaps painted almost as soon as the being made and too quickly (then there might be a solvent issue) the gel-coat should of stopped any end strands being exposed (absorbtion into the end strand issues that you see around poor repairs) but that taking the panel back to the surface gel-coat and re-starting the paint process in paintshops water free cures the problem (given that I have never hurried cars that are having re-paints through the paintshop and enforce a no water process then therefore perhaps by luck more than judgement end up being dry for several months). Adrian@
Neil .....post me direct with you address etc.
Edited by adrian@ on Monday 4th December 20:36
Would be an amazing phenomenon if it had happened that way. Am I correct in assuming that the M was the first car TVR painted with a water based acrylic paint?
as you say. Solvent pop is quite common on Hurriedly painted cars or where too heavy a top coat is applied. I would still tend to plump for water entering the paint via gel cracks or pin holes etc.
PS mailed you directly.
Neil.
as you say. Solvent pop is quite common on Hurriedly painted cars or where too heavy a top coat is applied. I would still tend to plump for water entering the paint via gel cracks or pin holes etc.
PS mailed you directly.
Neil.
I'm not sure about the water based paints ....I think that is a more recent thing and a health and saftey issue.... the high temps involved might upset an older TVR, although my paintshop uses this method normally, they have a special paint mix with a warm oven with an over the weekend air dry for my cars (the car gets painted last thing on a Friday, the booth closed whilst still hot and left till Monday) then the car gets left until later in the week before checking, nibbing back and hand flatting and polishing. These are method that we have used for a long time...and even then it throw up quirks that we never quite get to the bottom of. Adrian@
I've got a 1976 Taimar which is quite original including I think the paintwork, which is in quite a bad way with big/little blistering on most of the panels including the tailgate Adrian has seen it(he also owned at one point)and I tend to believe his description of what has gone wrong.I thought osmosis mainly affected boats below the waterline(fully immersed for long time periods)and why do baths and shower trays not be affected,could it be because they are not painted?
Hi Folks,
Just a quick update the car is in awaiting the respray and they have taken the drivers door back to the gelcoat (all nine coats!) and thankfully there is no problem with the fibreglass it seems to be as Adrian says and just bad painting practice with no watertraps in the air lines.
Thanks for the words of wisdom Adrian.
Grant
Just a quick update the car is in awaiting the respray and they have taken the drivers door back to the gelcoat (all nine coats!) and thankfully there is no problem with the fibreglass it seems to be as Adrian says and just bad painting practice with no watertraps in the air lines.
Thanks for the words of wisdom Adrian.
Grant
've noticed another phenomenon that seems to be associated with two part urethane paints such as Awlgrip, Imron, Durethane, etc.
if a car cover is used that traps moisture against the paint blistering can occur. looks just like a case of solvent popping or small gelcoat blisters. of course this could just be a coincidence, but i've seen it happen with paint that hadn't shown any problems until the car was covered and left outside. of course i live in florida and there's no shortage of rain, humidity, and heat.
if a car cover is used that traps moisture against the paint blistering can occur. looks just like a case of solvent popping or small gelcoat blisters. of course this could just be a coincidence, but i've seen it happen with paint that hadn't shown any problems until the car was covered and left outside. of course i live in florida and there's no shortage of rain, humidity, and heat.
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