65RDSTR

That is the question.

I have fiberglass panels on my car that came from all 5 years. I dont think there is a single panel that hasnt been repaired in some way. Im going over the car with a fine tooth comb and everything will be perfect when it comes time for paint but I have heard that the different density fiberglass repairs will expand and constrict differently in the hot sun causing paint to crack. What is the best way to stop this. Is the Gelcoat product from Ecklers good stuff. I heard it discribed as a polyester primer and not that hard. I guess I want to give the car a good hard consistant surface to paint on. What are some of the oppinions here. What do you guys have between your glass and paint? Anyone with a repaired body out there that has had problems or has not had problems? I was planing on painting the car black (I know black shows flaws but I plan on not having any) but my second thoughts are that black might cause too much heat and therefore paint crackling. My second choice would be Silver. I would think the paint wouldnt get very hot. Is this true?

Cmacsvette

65RDSTR,

To avoid the shrinking at repair points, baking those raw areas at approx 200 degrees is your ticket. Many SUPER paint jobs, have suffered this shrink thing here and there and a lot of it due to the lack of heat to aid in the curing process. I don't know if you are doing all the prep and color but you can get one of these infrared curing lamps at your local auto paint supply stores. One of the BEST, approx 200 bills you will ever spend. Yes, a black car will get hot due to the fact it absorbs, where a lighter color can reflect. All the more reason you want to beat the SUN to it and get these areas cured out before fillers, gelcoat, fillers, primers, color, etc., etc. If I were you, stay with the black, I am.
You said panels from all 5 years, do you mean repro panels, white, gray and black and are repro panels. Or do you mean white, gray and black panels and are OEM panels, bonded many years ago?
There is a lot of discussion out there on OEM vs Repro panels. As Jerry says (the owner of Corvette Image), his new panels contain more porosity than do the OEM's. He wants to see 18 to 22 mils(approx) of gelcoat on his panels before primer and color. I was at his factory a few days ago and saw that he is gelcoating new panels before shipping now. He told me,he wants the end user out there to have a jump on sealing these panels good. But still if you sand through it for what ever reason, like doing a dish grind of a seam, etc. you must apply more gelcoat. I brought this up because I saw the word density in your post.
I like Eckler's gelcoat and is the only one I'll use. There are pro shops across the nation which will say the same. It is very hard and one of the reasons someone might of said it was not hard, was due to the fact it was not mixed correct or it was to old and where the primer came from, I'm not even going there. Do I know of or heard of anybody who has had a bad glass day with their gelcoat, no.
I like to bake my gelcoat after initial cure to approx 140 plus. Some guys like to bake em in the hot sun for awhile, another good idea to aid in the cure out of the gelcoat. If you are going to use one of these lamps, get yourself an infared thermometer so you can check the surface temp of the glass area that you are curing, this well keep you from getting to carried away with the heat.
I guess it's back to what many say, prep,prep, prep, etc., this is the BIG factor in what makes or breaks a SUPER paint job. Good luck.

Craig

aworks

First lets start with the gel coat thing. As you said in your post,Ecklers so called gel coat is not gel coat. It is a high build polyester primer. And yes it works very well. Most polyester primers work well if mixed and used right. Now as far as heat go's the more the better. 200 is a good goal to reach. The temp. a black car will reach in the hot sun is very high. As stated above, heat lamps are a good sorce of heat and you should keep track of the surface temp. The heat should stay for at least an hour if not more. Even after a heat lamp is used on your repairs it would be a good idea to put a few coats of color, black in your case and let it sit out in the sun for a few weeks. I tint my primers dark grey and leave the body out in the sun for as long as possible. It also helps to wrap the car in black plastic. This will help raise the surface temp. Do not be in a rush to paint the car. Even after all this you may still see some of the repairs in the hot sun. Theres no way to be sure. Good luck Brian G.

Cmacsvette

Brian,

You mentioned you tint your primers dark gray. I was just wondering, is that U-POL/system20 from our UK brothers. If it is, let me know what you think of it or if you have tried it and its high build capabilities.
Thanks
Craig

DansYellow66

The description of your car's body condition is slightly worse than mine, but not by much - I had two good original doors and the roof that were not in need of repair or hadn't been replaced. I used a heat lamp and sunshine to cure out my fiberglass work and then used Eklers Gelcoat under my lacquer paint (painted about 1993). Other than a couple very small pits in the original fiberglass that have very slightly sunken (can be wet sanded and polished over they are so shallow) nothing else has shown through on the body. It's yellow instead of black but I had a lot of body repairs and dish ground out all my factory seams and glassed them in. Other than being a mess to use in the garage (overspray will stick to anything exposed) and being tough to block sand initially (loads up the sandpaper), Eklers gelcoat seems the way to go. I probably started sanding on mine to early and leaving it out in the summer heat for a week probably would have cured it a lot better initially. I use to read a lot of articles back in the eighties and early ninties that recommended spraying gelcoat over minor stress cracks to seal them - instead of repairing them. Don't buy that - any stess cracks have to be repaired with fiberglass or they will come through the gelcoat. Fortunately I didn't fall for that, but I had couple very small ones in jamb areas that I lost track of in my body repairs that didn't get glassed in and they did show through of course - but since I didn't repair them I don't consider their coming back to be a failure of the gelcoat. I think from the description of your car I would recommend using gelcoat.

Dan

67tripwr

You will find that technology changes all the time. I have found, that many body shops have done away with gelcoat! The key word here is
"Catalyzed Primer". The ease of use, and the way it keeps things from coming through the paint!

In my book gel coat is a thing of the past, and with modern paint/prep technology, it is not needed!

John McGraw

The Gelcoat from Ecklers is just that, nothing but polyester resin. It differs from a polyester primer/surfacer in that it has no inert material in it to make sanding eaiser. I feel that it leaves a much more dense, hard surface that is more resistant to cracking because of this.
Now for the bad. Take it from someone who has used it a lot, that it is a bit*h to work with! First of all, it has a parafin wax in it that forms a layer over the finished spraying that aids in curing. You have to sand the parafin wax off, and that will clog a lot of 80 grit paper. After that is done, you will need to sand the entire surface of the gelcoat to remove the orange peel. If you are thinking that this is no big deal, think again! Because there is no inert filler in it like primer surfacers, it sands very hard, and plan on spending many hours in this step. Also, buy cheap gun to shoot it with, since it is just a matter of time before you catalyze it too much or the ambient temp is too hot, and the stuff will set up in your gun before you can clean it out!
After this you will still want to use a catalyzed polyester primer/surfacer for fill and blocking. The gelcoat is not meant for taking out ripples and defects in the body, it is meant to seal old bodywork and give a strong hard surface to start a new paint job on top of.
If you are doing the work yourself, that additional work is just some more of your time, but if you are paying for this work, it can add up to a substantial cost added to the finished job. I have painted cars with it and painted cars with just straight polyester primer/surfacer, it just kind of depends on the condition of the body.
The best indicator of how durable it is, is when you strip a car that has been gelcoated in the past. When you apply the stripper, it attacks every layer, even the polyester primer, but it does not remove the gelcoat! The primer is somewhat porus due to it's large content of inert material, and the stripper will soak right in. The same thing can happen with solvents on some paint types, causing blisters to pop up in the hot weather. This isusually due to improper application of the finish, but the gelcoat will prevent this from affecting layers below the gelcoat.

Regards, John McGraw

jrs 427

One of my coupes sat outside after the paint was stripped. It was also block sanded in places to show fine fiberglass hairs. I took it to a boat repair facility where a double coat of gel coat was sprayed in these areas, sanded, and baked. Then the complete body was given two more coats and sanded in between. It is not a cheap process but the result is stunning and arrow straight. There was no accident damage so I feel when the black topcoat is applied it will retain its mirror finish. With the cost of materials and the hours of labor involved I feel this is the best route to travel. Do it once, do it right !!

VOIPGUY

Since we are on the subject of Gel Coat, has anyone tried the new Evercoat Single Step Gel Coat ?
http://www.allaboutboating.com/store...M+GEL+KOTE.htm

It is designed to cure without the typical relaese agent that is needed for other types of Gel Coats.

I bought a Qt. for testing and sprayed it on a piece of fiberglass.
It dries to a very hard non-sticky coating. It sanded like Gel Coat, very hard.

I'm going to spray my 59 later this summer.

Scott

DansYellow66

I think my experiences paralleled John's exactly - the parafin surface, the clogged sandpaper, the hours of sanding, the one pot that started to cook off in the gun, etc. Fortunately I completely covered my garage floor with plastic or it would still be black today. Still, if your car has had a lot of body work gelcoat is probably a wise move.

65RDSTR

Thanks guys these are the answers Im looking for. What color does it come. I would like to tint it black so I could leave it out in the sun to get hot.. The Ecklers add says it takes two gallons to cover the whole car. Is this about right? What do you use to clean your gun? MEK?

John McGraw

It comes in black, so that is one thing you will not have to do. Two gallons should be about right, maybe a little too much, but better too much than too little! Lacquer thinner will clean out the gun as long as it has not started to set. Watch your cataylst real close, it is very easy to make a batch to hot in warm weather.

Regards, John McGraw

Cmacsvette

65RDSTR,

John is right on, know your ambient temp. You will get instructions with the gelcoat, read them carefully. Just a few tips, I use a syringe to stick into the MEKP(cataylst), this way I know exactly how many cc's I've mixed. Everybody has diff. ways and that is just fine, whatever works for you. I like an exact starting point, so I can make adjustments from there as I move along. As said, it's easy to mix it to hot in warmer temps, but you can make it to hot in cooler ambients as well, when your increasing the MEKP.
The instructions will give you pot lifes as well as other info based on temps. Be careful with those printed minutes on pot lifes! Example, temps between 60-70 @ 15 cc's(per qt.) gives you a pot life of 30-45 mins. You can be spraying, oh lets say 28mins and the atomization of the fluid is just fine and in just a matter of very few mins. or just another couple pulls of the trigger, the atomization of the gelcoat leaving the gun changes. (splattering) Watch for this sign, it normally means the gel is starting to kick in the pot. In my book it's time to clean the gun. Know your gun and how to take it apart. Always be ready to be able to take it apart and the pick up tube off. Have a piece of welding rod or coat hanger wire ready, long enough to span the full length of the pick up tube. Besides lacquer, have acetone, brushes, and tools on hand too. Again, everything is predicated on temps and how much MEKP was added. The #'s you get in the instructions are just rule of thumbs. As you can see from the example of 60-70 degrees, that is an approx. and in a 10degree span, times change. Rule of thumb, expect to clean your gun after the first qt. Some guys make it two or whatever, you will be the judge of that by keeping track of your ratios vs temp. and watching the atomization of the fluid leaving the gun. I'm not trying to scare you, it's not rocket sicence and it's not hard. Trust me, the gelcoat right now, where ever it is, is not sitting around with a bunch of other coats, planning a terrorist attack on you, your family, your car, your gun and to screw your life up forever. Just remember that the coat has a set of rules it plays by and as long as you are "AWARE" of them and adjust, nobody or thing gets hurt. If you do screw up, guess what, once upon a time, I beat you to it.
I didn't mean to get so windy, but I just wanted you to have a big jump start. All the guys above have given a lot of good info and have done the same for you.

Craig

aworks

I only saw the Ecklers primer one time. I never used it myself. I had a customer bring me his 71 that he had done the body work on and used the Ecklers primer. He brought me what was left with the instuctions. It was not black it was very light grey. And it did not have PVC sprayed over it as real gel coat would. PVC is the wax coat. Now this was about 8 years ago. Did Ecklers change it? Real gel coat is just tinted resin and can be bought at any place that sells composite mat. The Primer I use is made by Fourseal. I buy it from a compostie mat dealer in Ct called LBI. It is just gelcoat with talc added so it is easier to work with. No PVC needs to be sprayed after. You can tint it as dark as you want. Maybe Ecklers has changed there stuff over the years. If so I am giving wrong advise. Brian G.

John McGraw

Brian,
The stuff that we are talking about is just a traight tinted resin with some wax in it to form the cure layer. No talc or any other material to aid in filling or to make easier to sand. It is a drak black in color. The wax floats to the top after spraying to form a curing membrane. Ecklers has been making it for many years, but few use it due to the additional cost of labor.


Regards, John McGraw

magicv8

Mine was gel coated - both paint jobs in 17 years.

aworks

I'll have to order some from Ecklers and try it on something. John the stuff that I saw was not as you say. I never gelcoated whole cars cause the PVC is a real pain. I'll try it and see what I think of it. The stuff I use is made for boats. It works super and creates a very hard surface. I lighty sand it so I don't take down the mil thickness much and then use urethane primer over it to do the finish work. I have always liked it but maybe the Ecklers stuff is better. Do you use a gelcoat gun? I have one that I use when I make my own parts. Even an old Binks #7 won't spray regular gelcoat very well.

Scott Marzahl

I'm about to the point where I will be shooting a Gel Coat myself. If Ecklers is simply black tinted Polyester finishing resin (with Parafin added for the cure) why pay that Ecklers price for it, gallons of polyester resin sell for about half the cost of the Ecklers stuff? I was going to use Evercoat SlickSand, however like John brought up, it contains lots of fillers like talc that are too pourous for a solid base coat. Corvette Image uses and sells Evercoat Gel Coat which one needs to spray the PVC over it for the cure. The new one step Evercoat product looks interesting. I only want to shoot this stuff once, so I would appreciate any feedback.
Thanks,
Scott

my58

I know this is really going backwards but..

What is the process needed prior to gel coat.

Do you strip all previous paint and remove any fillers found then apply gel coat and then start the small repairs then prime
or
Do all the repairs and then gel coat then prime.

Yep basic questions but before long the bodywork part of my project will start, so I best start getting better educated from the experienced.

Thanks for allowing some of us beginners to learn from your efforts.

Solid327

Howdy Craig.

Hadn't seen you on here in awhile. How's your Stingray coming?

Guys, I wanted to chime in on this interesting thread. Has anyone ever heard of or tried Awlgrip? It is a marine product with similar characteristics to "gelcoat". I think it is a more modern formulation. Anyway, it was used in the restoration process on the body of a 53-54 Corvette that Chip Miller was involved with a few years ago. I forget the details of the car but the body was in very bad shape and they were going for a concours type restoration. There used to be a good website up on the body (along with the rest of the car's) restoration. Not sure if it's still up or not. A shop in Florida did the work.

I personally don't like the idea of using a gelcoat process unless it is absolutely warranted. Any guesses why Corvette Image panels are a different porosity, (since they are press molded like originals) over OEM/NOS vintage panels?? What about Schimershiem (sp) panels?