MG-Cars.info

Welcome to our Site for MG, Triumph and Austin-Healey Car Information.

Parts

MG parts spares and accessories are available for MG T Series (TA, MG TB, MG TC, MG TD, MG TF), Magnette, MGA, Twin cam, MGB, MGBGT, MGC, MGC GT, MG Midget, Sprite and other MG models from British car spares company LBCarCo.

MG TD TF 1500 - Acrylic Lacquer & Humidity

Had a dive into the archive on this one but was overwhelmed with irrelevant info. I've had some painting on my to do list since last September however the humidity, which I check daily, has been consistently over 60% for almost all of that time, as it's been almost constantly wet & miserable. Today the sun is shining & the humidity is around 92% according to the weather bureau. Maybe it'll drop once the fog clears? I'm using acrylic lacquer (as that is the closest to the original finish) but not in a humidity controlled environment. Changing the type of paint is NOT an option. Question is how best to proceed? I spray in the open & want to avoid paint bubbles caused by high humidity. What % do I need the humidity to drop to before I can safely apply my acrylic lacquer finish coats? Cheers
Peter TD 5801
P Hehir

Talk to your paint supplier about 'anti-blushing' additives.

Paint cools as it dries, that causes condensation (blushing). This can be controlled up to a point. Also, call a body shop or two and see if they can give you a little guidance. you might need to find someone over 50 though, not many young-uns know much about old lacquers.

You might also pop into a few hot rod forums. Many helpful folks at:

http://www.hotrodders.com/forum/paint/

I painted lots of cars in the 70's with nitrocellulose lacquer. Oh, how I miss it.

.....
MAndrus

Peter. I don't have an answer as it has been many years since we've been able to use lacquers in my area of Ca. Obviously the lower the better. I would think around 30% maximum. But you should be able to contact the supplier and get a spec sheet for the product your using. Or maybe even the manufacturers website may have the info you need. Definately keep your tanks dry. Run a section of line up hill to a dryer/ separator and bother length of line to another inline filter at the gun. And drain them repeatedly during your spray time if the humidity is high. At least lacquers are very forgiving and since you will be laying down multiple coats of color you can nib down any perfections between coats. Lacquer is very forgiving.

Cheers

Bill Chasser jr
TD4834
W. A. Chasser Jr

Don't paint anything at 60% period. It will fog up. In fact I would be happier with lacquer at that humidity versus enamels. Even with fast dry thinners. They are really more for temperature versus humidity.

You need to get it down to 25% or less. Wait until spring/summer.
Christopher Couper

One problem using lacquer is using Lacquer primers that absorb moisture that gets trapped under the top coats.

Use white spirits to draw out the moisture just before the top coat is applied.

It is best to use a two pack primer that seals off.

We always wet rubbed between coats, that helps the Lacquer base coats seal.



Rod Brayshaw

Thanks Mitch & Bill. My acrylic however is in cans perfectly colour matched to the original YL5. Chris I had fully expected to be able to paint between September to March which is Sydney spring & summer but the wet weather has been relentless here & still shows no signs of letting up. I'm beginning to think 25% humidity is just a fond memory. I'd hoped for a dry winter & with my panels in the sun I thought I may be able to spray in the early afternoon. I did manage to respray my rear guards in the first week of January this year during a rare sunny break. See pic attached of my outdoor setup. Yet to be colour sanded & polished. Thanks for your input guys.
Cheers
Peter TD 5801

P Hehir

Rod I use a wax & grease remover just before applying the top coats, well actually before every prep coat. I guess that has a white spirit base? Cheers
Peter TD 5801
P Hehir

No Peter, Wax and grease remover will not draw out moisture.
Rod Brayshaw

Thanks Rod. I'll add a wipe over with white spirits as the next step after the wax & grease remover. Cheers
Peter TD 5801
P Hehir

hmm. I am no expert but i would be tempted to do it the other way around. Wipe with white spirit and then with de-greaser.

White spirit will leave a trace when it evaporates and I wouldn't want it interfering with the paint...

Dave
D Moore

Nor am I Dave so I'm willing to defer to those with greater knowledge. As I do everything on the car, except for the chrome plating, my approach is to gather as much information that I can & then proceed with caution. Cheers
Peter TD 5801
P Hehir

Peter: Bring your car to California. We have plenty of hot dry air here right now. You will probably have to buy some slow thinner in fact which we will gladly sell you.

But bring your money too because we will charge you and arm and a leg for all the permits, environmental charges, special equipment and fees etc to paint your car :-)
Christopher Couper

That's what I like about you Chris. You go out of your way to help. I reckon I should be there in about a month. -:) Cheers
Peter TD 5801
P Hehir

Rod is right Two pack primer is by far the best primer under Acrylic Lacquer, I always put off painting until the weather is right unless I am in a temperature controlled spray booth.
I always add some clear to my Acrylic paint it gives it extra depth, not too much as I can go milky.
I have just re done the front of my Chrysler.


Regards

George

G Mills

Posted the wrong photo front of Chrysler painted in Acrylic ( re paint)

G Mills

Looks great George. I'd be very happy with that standard of finish. Cheers
Peter TD 5801
P Hehir

For the first time in years the humidity in Sydney is down to 11% tomorrow! So final touch ups on the tub at long last. Cheers
Peter
P Hehir

Peter,
Never in all my years have I experienced the relative humidity in this part of Europe or in Ireland (where I grew up and it only rains twice a week-once for three days and once for four days!) drop below about 55%.
I cannot imagine 11% relative humidity or do you use a different scale in Oz? It is currently 79% in Düsseldorf as the rain never let up yesterday.

Regards
Declan
Declan Burns

Here's the evidence Declan. http://www.bom.gov.au/places/nsw/campsie/forecast/detailed/#d2017-01-24.

It's from the Bureau of Meteorology. It actually drops to an incredible 8% at 5 pm tomorrow! Cheers
Peter
P Hehir

Peter,
That's incredible-strange country!
Get your spray gun ready!
Regards
Declan
Declan Burns

I'm using cans that come from your part of the world in Germany. They arrive here with the propellant and the paint is colour matched and filled here. The nozzle technology is superb giving a finish equal to my spray gun. Enables me to paint the panels in stages as I don't want to upset the tenants in the block of flats above the garage I rent. Cheers
Peter TD 5801
P Hehir

And the Germans probably added moisture to your paint cans so they would be compatible in their normal humidity. :-)
Christopher Couper

Humidity around 50% here today. Hope you are having better luck with your painting than I am Peter. Yesterday I put what could have been a final top coat on one of the rear mudguards of TF2071 and, considering the last time I sprayed a car was 1974, I have never sprayed 2K before and I am using a new gun, I was pretty pleased with the result.......
Until I turned around to clean out the gun and the airline to my respirator rubbed across the surface! Despite wearing a full face mask, all doors closed, and 2 compressors running my wife still heard the expletive from acros the garden.
Chris
C I Twidle

My guess is it rhymed with duck Chris. About to head off to the garage now. Cheers
Peter TD 5801
P Hehir

I have had the pleasure of seeing George Mills Chrysler a few years ago.

The standard of the car is exceptional. A credit to George and his standards.

Cheers
Rob Grantham
TF3719("Aramis"), TF9177("Athos").
Rob Grantham

This thread was discussed between 29/06/2015 and 12/02/2019

MG TD TF 1500 index

This thread is from the archives. Join the live MG TD TF 1500 BBS now