Preparation of welds for painting

[wally57]

I have a question for the spray painters out there or those with experience with high quality paint jobs.  A friend of mine is about to paint a fully restored phase 3 GTHO Falcon. He has been given a number of quotes from high end paint shops ranging from $16,000.00 to $30,000.00 for a show quality job.

In almost all cases the painters mentioned spraying all welds with some kind of coating that seals up pin holes etc and dries almost as hard as metal. This apparently prevents leaching of moisture through any defects in the weld metal regardless of how minor they are. None of the painters actually gave him a brand name of the coating they use but in each case the cost was fairly high for the treatment.

My question is does anybody have any idea what this coating would be and if at all possible where it can be purchased from.

 

Wally 57

[Sirpent]

"BOLLOCKSSSSSSSSSSSSSSSSS"

 

Opps sorry I sneezed, what was the question again ?

[handsandwhich]

Doesn't help with the question but is this a genuine phase 3 or replica?

 

BTW what welds are there that are visible and need to be filled in? I'd say take it back to the person who put all the pinholes there in the first place and have them fill them 

 

 

[Sirpent]

I should elaborate on my response.

 

The true mark of a restored vehicle is how much devil there is in the detail, and that includes preserving the factory detail.

 

When I look at any car I always check the seam spot welds, its the first place that will tell you if a cars been smashed or a panel replaced, those small spot indentations are worth their weight in gold on an original car, so much so that years ago I used to even re-create them using a nail head in body filler in places where a repair had been done just so the finish would look right.

 

How do you tell an A9X from a standard Torana shell? they have twice the frequancy of welds along the seams as done by the factory.

 

Secondly, the only thing you will ever see along and across a seam is brush on seam sealer which is fine and even when put on across spot welds still allows them to show through, take a look at any car and you will probably spot this.

 

Why on earth any one would even contemplate doing what you mentioned  to a collectors car is beyond me, Im not having a go at you Wally but the restorer needs to re-examine what he is charging for because to me its a devaluating exercise.

 

Cheers

 

John

[wally57]

Guys,

 

Sorry I have been out of the loop for a couple of days and haven't had the opportunity to comment until now. I am not a painter and don't know a lot about the process, that's why I went to people who everyone up here was recommending to me.

The paint shops I have mentioned are all high end shops. One in particular only repairs and paints classics, show cars and Hot Rods etc. They are regarded by many people as one of the best in the industry, certainly in the Hunter Valley. They are one of the first ones rodders, street machine owners, etc recommend.

John I may not have described the process well enough previously. The compound is painted over welds etc where rust repairs etc have been completed on both sides of the weld. It penetrates and seals any holes, cracks etc that may be in the weld material. Once dry they rub or wire brush the welds to remove any excess compound and then follow the normal process of filling and shaping the panel.

Handsandwhich : Firstly It's a GS that has been turned into a HO. May not be genuine but it has cost about $80k to build and is as genuine to look at as can be. Secondly I may not know much about painting but I do know a fair bit about welding. I manage a large fabrication workshop with 60 boilermakers who are all pressure qualified using the Mig process. As good as they are, every so often they still get a bit of porosity from a puff of wind, or the contamination of the weld pool. Of course they grind it out and reweld it when they see it, but they still have welds that will fail on occasion. If you think a panel beater or home handyman can weld up panels in a car without the slightest bit of porosity or minor surface cracking from rapid cooling your kidding yourself. They may not be all that visable to the eye but they will be there, and they will allow water to pass through the weld. You only need one or two in a weld and your paint job will be RS in a couple of years time if they are not properly sealed.

If I am going to spend good money on a paint job I don't want rust coming back in a couple of years so I want to take all possible precations to make sure it's right. Thats why I posed this question.

 

Wally

[mossy]

From what I have researched before even the best looking welds can have pinholes in it, I have also heard some guys will use a fine smear of fibrefill over the weld to seal any pinholes, if any ,to stop moisture getting in, don't know if this is a good practice or not though.

[wally57]

Just spoke with my mate, he said it was definitely sprayed on. When he was in the painters workshop he saw them doing an XU1 body and said it was a pale blue colour. After speaking with him it appears I may have misunderstood the exact process as explained in my last post. He says they dont rmove it after it drys they just prep over it. Anyway he is going into the painters again tomorrow to check progress and will try to get a brand name so I can research it further. Once I know I will post it for everyones information and further discussion if appropriate.

 

Wally