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Tue Nov 18, 2008 4:50 pm

Gonna put the buggy in primer soon. I did a bunch of reading here, and other places, and i know that i will need a "High Build" Primer? What product would you suggest for this? Also, i have heard that i will need the "Bull Dog" additive for the paint because of flexing, but will i need this for the primer too?

This will be the first coat, and then back to sanding again. I swear, my arms are gonna look like pop-eyes!!

Thanks for the help!!

Tue Nov 18, 2008 6:08 pm

I am not an expert, but will tell you my experience. I patched up a buggy body 6 years ago, used the Bulldog" adhesion promoter prior to primer, did all with spray cans, then had the body painted and clear coated, from day one, I could see areas that bubbled, but it was way under lots of clear coat, so I lived with it. A few months back, I had an engine fire, did not do any damage to anything, but the paint around the back of the buggy, so I decided to repair it, some areas I had applied a 3m protective film to, when I removed this film, the paint came with it, on these and other areas, any primer I used, would wrinkle the edges of the old paint. The only thing that worked was spraying those areas with Kustom Shop DTM epoxy primer/sealer, this can be mixed almost like a build up primer, or reduced to use as a sealer, I imagine any epoxy primer would probably be the same, but in any case, it adhered to the old paint, and sealed it so that it eliminated all the problems I was having.
If I ever do another buggy with a repaired/patched up body, I will spray the whole body with the epoxy primer (not easy clean up, next to impossible after it dries, hell to sand too), wet sand smooth, then use a base coat, clear topcoat. By the way, I did all the painting with a turbine HVLP sprayer.

Wed Nov 19, 2008 3:28 am

Make sure to get rid of any old paint and hit the gelcoat with wax and grease remover then give it a good sanding with either 120 or 80 grit, not too much or you'll go through the gelcoat, before priming. That'll open up the pores of the gelcoat and give the primer lots of tooth to adhere to. I've never painted anything as large as a buggy but this has always prevented any adhesion problems on every project I've done.

Wed Nov 19, 2008 7:47 am

I use Evercoat G2 primer on all my fiberglass cars. It fills in lots of scratches, sands well, is easy to apply and affordable.

I buy it at www.autobodytoolmart.com

I mix as directed, but add 10% (by volume) of acetone to help with the flow. I also use a 1.8 tip on my gun. You also need to be sure to strain after mixing and before adding to the cup.

Wed Nov 19, 2008 5:31 pm

Cool, thanks everybody. I still have a ways to go on the sanding, just trying to get everything together for the primer, and then sealer.

Thanks again!

Wed Nov 19, 2008 11:13 pm

Stay away from Bulldog adhesion promoter on something like bare fiberglass. The reason it will wrinkle is because it's a 1part product. All your good paint products are 2K. The solvents in the top coats will soften the Bulldog product causing it to lift. Especially when layers of paint are sanded through during repairs. I've only used Bulldog on small plastic parts that I rattle can or airbrush.

The G2 from Evercoat as mentioned will work great. Make sure to let it flash off between coats, especially in the nooks and cranies where it tends to take a little longer to flash.

Wed Nov 19, 2008 11:50 pm

Eric Anderson wrote: Stay away from Bulldog adhesion promoter on something like bare fiberglass. The reason it will wrinkle is because it's a 1part product. All your good paint products are 2K. The solvents in the top coats will soften the Bulldog product causing it to lift. Especially when layers of paint are sanded through during repairs. I've only used Bulldog on small plastic parts that I rattle can or airbrush.

The G2 from Evercoat as mentioned will work great. Make sure to let it flash off between coats, especially in the nooks and cranies where it tends to take a little longer to flash.

So, do i need to add anything to keep the paint from cracking or breaking due to flex? Buddy of mine told me to do it. He owns a body shop, but i think he might have his feeling hurt that i am not paying him to do it. He just seems kinda hinky now. Hes just to damb expensive!!

I dont plan on taking it all the way down to the bare glass, i am doing it like tstracy39 said, and just scuffing it up and cleaning it. There will be some bare glass where i am doing some repairs and patching holes tho.

thanks again

Thu Nov 20, 2008 7:37 am

I have never used any additives and have never had a problem. The glass is pretty strong. Press in on the door skins on many of today's current production cars...they will flex. Today's paint technology allows for flex.

Use the G2...you will be happy.

I have also never used a sealer over the G2. It won't do any harm using one, but according to Evercoat you don't need one.

Thu Nov 20, 2008 3:32 pm

mrme wrote: Eric Anderson wrote: Stay away from Bulldog adhesion promoter on something like bare fiberglass. The reason it will wrinkle is because it's a 1part product. All your good paint products are 2K. The solvents in the top coats will soften the Bulldog product causing it to lift. Especially when layers of paint are sanded through during repairs. I've only used Bulldog on small plastic parts that I rattle can or airbrush.

The G2 from Evercoat as mentioned will work great. Make sure to let it flash off between coats, especially in the nooks and cranies where it tends to take a little longer to flash.

So, do i need to add anything to keep the paint from cracking or breaking due to flex? Buddy of mine told me to do it. He owns a body shop, but i think he might have his feeling hurt that i am not paying him to do it. He just seems kinda hinky now. Hes just to damb expensive!!

I dont plan on taking it all the way down to the bare glass, i am doing it like tstracy39 said, and just scuffing it up and cleaning it. There will be some bare glass where i am doing some repairs and patching holes tho.

thanks again

No need for a flex additive at all. If you are worried about it cracking you should strip the old product off. Too much product will cause it to crack or fail in the future. Flex additives only slow the cure process down. They were desigined to allow the body shop a window of time that the paint was more plyable for reassembly of plastic bumpers,ect. It will fully cure at some point in time. Todays products are more than flexible enough for normal wear and tear without additives. Flex also makes the clear unbuffable for days, and yellows the clear making the color darker.

Thu Nov 20, 2008 4:41 pm

adhesion promoter doesn't have anything to do with paint flex.

flex agent is what is added to help prevent paint from cracking. typically its added in the clear coat. Not familiar with evercoat primers and products other than their body fillers and fiberglass.

generally I use PPG. I know their flex agent is #814. I wouldn't recommend using it though if you're using evercoat products. Id look to see if evercoat makes a flex additive.

epoxy primer is used to rust prevention on steel parts. Its also commonly used on aluminum for promoting adhesion.

On fibgerglass I'd recommend getting a solid cut with some 150 grit sandpaper. Epoxy over that will help to get some good adhesion. One coat is all you need. Next get your build from high build 2k primer.

Thu Nov 20, 2008 7:20 pm

jspbtown wrote: I use Evercoat G2 primer on all my fiberglass cars. It fills in lots of scratches, sands well, is easy to apply and affordable.

I buy it at www.autobodytoolmart.com

I mix as directed, but add 10% (by volume) of acetone to help with the flow. I also use a 1.8 tip on my gun. You also need to be sure to strain after mixing and before adding to the cup.

What color is that. I was gonna paint it blue, but the more i look at that, it looks bad ass, and i already have a sand rail i painted blue.

Thu Nov 20, 2008 7:25 pm

Eric Anderson wrote: mrme wrote: Eric Anderson wrote: Stay away from Bulldog adhesion promoter on something like bare fiberglass. The reason it will wrinkle is because it's a 1part product. All your good paint products are 2K. The solvents in the top coats will soften the Bulldog product causing it to lift. Especially when layers of paint are sanded through during repairs. I've only used Bulldog on small plastic parts that I rattle can or airbrush.

The G2 from Evercoat as mentioned will work great. Make sure to let it flash off between coats, especially in the nooks and cranies where it tends to take a little longer to flash.

So, do i need to add anything to keep the paint from cracking or breaking due to flex? Buddy of mine told me to do it. He owns a body shop, but i think he might have his feeling hurt that i am not paying him to do it. He just seems kinda hinky now. Hes just to damb expensive!!

I dont plan on taking it all the way down to the bare glass, i am doing it like tstracy39 said, and just scuffing it up and cleaning it. There will be some bare glass where i am doing some repairs and patching holes tho.

thanks again

No need for a flex additive at all. If you are worried about it cracking you should strip the old product off. Too much product will cause it to crack or fail in the future. Flex additives only slow the cure process down. They were desigined to allow the body shop a window of time that the paint was more plyable for reassembly of plastic bumpers,ect. It will fully cure at some point in time. Todays products are more than flexible enough for normal wear and tear without additives. Flex also makes the clear unbuffable for days, and yellows the clear making the color darker.

So i just wanna make sure i have this right. I am going all the way down to the gelcoat, and scuffing that pretty good, so i can used the evercoat g2, flash, have a smoke, then guide coat, sand, then another g2, flash, have another smoke, guide coat, sand, then seal, then paint. There will be no old paint left anywhere, and no flex product.

i had a feeling my "buddy" was steering me wrong.

Thu Nov 20, 2008 9:25 pm

Finish bodywork and sand with 180 or 220 before 2 to 3 coats of G2 with proper flash. Get the tech sheet on the product. Then guide coat, block sand until you get as sraight and smooth as you want. Clean, Seal and paint :)

The reason G2 is great for fiberglass is because it uses MEKP hardner. The same liquid hardner used for gelcoat and some fiberglass. The epoxy primer method mentioned is good for fiberglass too, but it's a slower method with more materials. After the epoxy primer dries...useually overnight, you still have to apply a primer surfacer to fill and have a product to block sand.

Fri Nov 21, 2008 6:33 am

Its Kirker metallic orange single stage with their Ultra clear coat. Dirt cheap, sprays really nice, and lays flat. Here is a picture after my amatuer spray and no wet sand and no buffing:

With the G2...a good week in the sun to make sure it is fully cured is a good idea. It will dry alot sooner, but letting it cure will help with the final sanding by eliminating any shrinking.

Fri Nov 21, 2008 12:20 pm

Yep, thats it. I love that color!! Mind if i borrow it?

Fri Nov 21, 2008 12:46 pm

Hmmmm...lets see...your in Florida and its in Canada....you should be safe!

Go for it!

But only if you post pics when done.

From the Kirker site:
FACTORY-PACKAGED ULTRA-GLO ACRYLIC URETHANE COLORS
PACKAGED IN 3/4 GALLON CANS
UA-11125 Bright Orange Metallic

And I used this clear:
ULTRA H/S 4:1 Clear

You can get it at www.autobodytoolmart.com. One 3/4 gallon was plenty.

Sat Nov 22, 2008 11:36 am

for any kind of fiber glass panels, use a Polyester primer. It actually uses fiberglass hardner. Nothing better for fiberglass. Period. Plus it doesn't shrink up like urethane primers. Great stuff.
Just about every paint manufacture makes it. PPG, Evercoat, Sherwin Williams, ect.

Sun Nov 23, 2008 9:45 pm

Eric Anderson wrote: Finish bodywork and sand with 180 or 220 before 2 to 3 coats of G2 with proper flash. Get the tech sheet on the product. Then guide coat, block sand until you get as sraight and smooth as you want. Clean, Seal and paint :)

The reason G2 is great for fiberglass is because it uses MEKP hardner. The same liquid hardner used for gelcoat and some fiberglass. The epoxy primer method mentioned is good for fiberglass too, but it's a slower method with more materials. After the epoxy primer dries...useually overnight, you still have to apply a primer surfacer to fill and have a product to block sand.

Not sure why you would let the epoxy primer dry overnight. Its meant for adhesion. Once its given its proper flash time you can go right onto high fill primer. Letting it cure just means it needs to be scuffed again to get the bite for the primer to stick, which is why it can be used. Using epoxy can actually save time if you go with a product like DP 90 (PPG) with a hardener like 402 which doesn't require an induction time. Mix, shoot,flash and go right on to high fill primer.

Sun Nov 23, 2008 10:44 pm

jracer6 wrote: Eric Anderson wrote: Finish bodywork and sand with 180 or 220 before 2 to 3 coats of G2 with proper flash. Get the tech sheet on the product. Then guide coat, block sand until you get as sraight and smooth as you want. Clean, Seal and paint :)

The reason G2 is great for fiberglass is because it uses MEKP hardner. The same liquid hardner used for gelcoat and some fiberglass. The epoxy primer method mentioned is good for fiberglass too, but it's a slower method with more materials. After the epoxy primer dries...useually overnight, you still have to apply a primer surfacer to fill and have a product to block sand.

Not sure why you would let the epoxy primer dry overnight. Its meant for adhesion. Once its given its proper flash time you can go right onto high fill primer. Letting it cure just means it needs to be scuffed again to get the bite for the primer to stick, which is why it can be used. Using epoxy can actually save time if you go with a product like DP 90 (PPG) with a hardener like 402 which doesn't require an induction time. Mix, shoot,flash and go right on to high fill primer.

There is nothing wrong with using epoxy primer. Letting it dry overnight is just my advise from experience. I use PPG at my shop I'm familiar with the products. Next time you do an overall try the polyester style primers instead of the normal primer surfacer. You will like it. You can spray it over epoxy primer if you like, but it's not necessary on fiberglass. DP 90 with 401 or 402 has a 1 week window for primers & top coats before its necessary to scuff and re coat. There is only a 30 to 90 min. flash time required for top coats. Overnight dry if you apply a body filler. I found over the years if you use DP epoxy primers prior to a primer surfacer it's best to let it cure over night.

Going straight through with the paint process without letting the epoxy primer have it's full week to cure, leads to some die back in the form of a slight texture to the finish, even after it has been cut and buffed. That's why I think it's a good idea to let it cure overnight before applying primer. Because it's not fully cured for a week. I wondered why it did this ( the slight texture in the clear day after buffing from time to time) until the question was brought up at the PPG training class I attended years ago. The instructor advised its best to let it dry overnight, even before color. He explained that epoxy primer is more for the complete paint job projects that required sealing a bare metal, aluminum, plastic, or fiberglass that was to be worked on as more of a long term paint job project. Not really a production shop product. In the past we used it as a sealer before painting, but this is only because PPG didn't have a good 2K sealer on the market and we were told DP was ok. I use PPGs V-seal now prior to color..no die back. I only use epoxy primers on bare aluminum or metal to seal it up after it's been stripped, and cleaned, to seal it up while it goes into bodywork.

Tue Jun 23, 2009 10:03 pm

Hi, new guy here. I'm getting ready to paint my VW powered Montage. I've asked a few different people about fiberglass primer. One guy said to use Slick Sand because it actually bonds to sanded gelcoat, raw fiberglass or any type of Bondo body filler, and it fills scratches and tiny holes better.
Another guy said to use Awlgrip because that's what the Pros use on fiberglass boat hulls. After reading the above posts, should I use Bulldog because the middle of my hood flexes. Now I'm more confused than ever. This photo was taken before I sanded the whole car with 220 paper. I want to have it repainted red. Should I use white or gray primer ? Does it matter ?
Greg
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