Removing paint

[jono]

I've decided to strip the paint myself from my Plus 2 project once I've completed the sill replacements - never having done this I am interested in knowing how others have approached it?

Firstly it would seem I am lucky as the car has only one layer of original paint and then a really poor thin repaint which looks like it wasn't even keyed before it was applied and can almost be removed with the thumb nail. Consequently there is little material to remove before you get down to what appears to be a fairly soft white primer (original?) and then the fibreglass. Would I be correct that the gel coat is the hard translucent outer 'shell' of the fibreglass and not the 'soft white primer' I've described above?

I've had some localised success using a sharp wood chisel and then hand sanding the 'white primer' until the fibreglass is just exposed and then taking the last traces off using 120 aluminium oxide paper so as not to damaged the fibreglass.

But I am going to need some power. I have a 3hp compressor but it only has a 50 litre tank and so air tools are probably out.

So I am now thinking of an electric DA - there are loads available but could someone say what I need - power, speed etc?

I don't want to spend a fortune, say £100, in case I give up mid way and bearing in mind I don't plan to start doing this for a living

any other paint removing tips gratefully received.

[alanr]

I am sure more qualified people than me will be along shortly with good recommendations..
However my concern would be with a DA is that you are going to generate a hell of a lot of dust powersanding and will need full protective suit and breathing apparatus to protect your lungs!

Alan.

[jono]

Thanks Alan,

a very valid point but I have a decent P3 respirator and am looking at the machines which have an extraction port to connect a vac (a lot of power tools have them now) - not complete dust elimination but it certainly improves matters

[TeeJay]

So I am now thinking of an electric DA - there are loads available but could someone say what I need - power, speed etc?

I don't want to spend a fortune, say £100, in case I give up mid way and bearing in mind I don't plan to start doing this for a living

Hi Jono.

Well this brings back some memories of hours and hours of painstaking work, removing all the paint from my +2.
All worth it when completed.

Like you I used wood chisels, also wall paper scrappers, a Stanley knife in a plastic holder.

My electric power tool was a DeWALT D26453, because it’s a variable speed random orbit sander, with dust bag & extractor facility. Purchased it for my paint job, but has come in useful since for many wood, metal and plastic projects.

Currently on sale at Amazon for £82, with free delivery for Prime members or EBay £80 with free delivery.


Edit:- Links removed as they no longer have the same prices.

Regards

[jono]

Hi Trevor,

That's exactly the machine I was beginning to settle on! - the right price and it comes very well reviewed so it's good to know it served you well.

Did you take it right down to the GRP or did you leave it at the 'white primer' stage (what I now believe is actually the gel coat)?

As far as I can tell the gel coat has no flexural strength and is only there as a release agent so I'm thinking it is probably better removed altogether in case it's hiding any underlying stress cracks that might otherwise go undetected?

Cheers

Jon

[TeeJay]

Hi Jono

Yes I did remove the white primer, to fully expose stress cracks and find other unknown repair areas.

Also to reinforce the pop up light bracket, the area where the rear boot hinges and several other areas around the body, with matt and tissue to ensure full adhesion.

[h20hamelan]

Glue, resin, gel-coat has no flexural strength.
1st, a release agent is applied to the mold
2nd, pigmented gel-coat
3ed, glass fibre reinforcement

Sanding, to see where stress cracks are. When you expose a fibre, moisture easily can find its way through the length of fibre. Even if this fibre is impregnated well, from movement of the body etc.

Before you add any coating, I think Re-Face is the recommended. Create an environment, and keep the humidity very low for a few weeks.

[rviani]

You could also consider doing a chemical strip. While some people feel this will damage the fiberglass this is not necessarily true and if done carefully can be accomplished without the damage to the gel coat possible from using a DA sander. I did this on my S3 with excellent results many years ago, but don't remember the name of the product I used - although it was nothing special.

[Andy8421]

Glue, resin, gel-coat has no flexural strength.
1st, a release agent is applied to the mold
2nd, pigmented gel-coat
3ed, glass fibre reinforcement

There has been much discussion on here whether Lotus used pigmented gelcoat or not. Both of my Elans have translucent, un-pigmented gelcoat. I would guess they used whatever was cheapest at the time.

[Donels]

I stripped my +2, all 7 layers of paint, and tried all of the various methods you've mentioned.

Eventually settled on an electric DA and a good breathing mask. It's daunting to start with but you soon become more competent, so start with relatively easy flat areas and build-up your skills. Initially stop at the white layer until you're confident then you can sand back to the gel coat. You have to experiment with different speeds and grits to find the best combination but I found 120 followed by 240 worked best.

It's a bit like archeology as you slowly reveal the cars history.

I bought an Erbaur DA from Screwfix but could not recommend them. The first one failed fairly quickly but Screwfix replaced with no problems. Like others have mentioned I use it for loads of other tasks now.

Dave

[Gordon Sauer]

My one caveat is whenever you can, I’d use an air file or a jitterbug sander, the idea that they’re going back-and-forth and the longer the board the better in terms of making a smooth surface on the doors and sides and horizontal surfaces; the bigger the air compressor the better because you’ll use quite a bit of air compressor to run an air file and one car I chipped with a chisel and another car I used a chemical strip and another car I sanded down and they all worked great, good luck Gordon Sauer

[denicholls2]

There are some who swear by hand block sanding, and they get very good results, so.

My method is a lot faster, and no, no electricity involved (depending on your light.) I stripped a whole Sunfish this way in an evening (About half an Elan, with some much harder spots to get at).

Tools: One very cheap, dull (but sharper is OK too) 10" slicing knife (cheap kitchenware).

Method: Holding the blade at 90 degrees to the surface, make contact in about the middle of the blade. Work the blade back and forth by the point with your fingers over the surface. The oscillation will detach the poorly-adhered paint from the fiberglass layer. And it works very quickly relative to expectations.

Damage to surface: None observed, the knife does not really contact it. And fiberglass resin is one mighty hard surface, which is why you can get away with this.
Damage to tool: During the surgery, I wore a flat spot about 1/16" deep in the blade about 2" long.
Cost: Labor plus under $10 for the knife.

I know there are readers cringing, but this worked wonderfully for me. And I had an orbital sander and paint remover available. I don't recommend either, the paint remover will leave scrape lines and the sander will leave swirl gouges you then have to sand out with finer grit. Either will take you at least 10 times as long for a worse surface. And you may as well forget about the eco-friendly removers, all they melt is skin.

[Darek Brewin]

I did my body down to the gelcoat over the summer and fall this year. I used an air powered DA spinning at 10,000 RPM. This was very effective, but I wished I had the electric one. I also went through over 100 sanding disks in the process. Any hard to sand spots I soda blasted. I did not enjoy this part of the exercise. I picked up a second hand 15lb pressure bottle and I think it made more of a mess than it did the job I wanted to.

I like telling people I spend $400 CAD on baking soda during COVID.

Darek

[jono]

Thanks for all these very useful tips and comments guys

I made good progress last night and got one wing completely stripped down to the white high build primer layer. I used a variety of wood chisels and a cork block - it spalls away quite easily but the attack angle is critical.

Not as bad as thought actually but I guess I'm helped by there only being two layers of paint on the car.

I friend has loaned me a Mirta sanding block with perforated sanding pads which you plug into the vaccuum so will give that a go tonight for removal of the high build down to the gel coat.

If I do a few hours each night I reckon I could be done and down to bare glass by the turn of the year

[Gordon Sauer]

Just a caution though because the gelcoat fills all those tiny little holes that are in the fiberglass itself and my sense is that you really don’t want to break through the gelcoat at all unless there are stress cracks. Then for the stress cracks I did really thin cloth and then even regelcoated that so the body still was complete with gelcoat. Gordon Sauer