-
Hi Guest!
You can help ensure that British Car Forum (BCF) continues to provide a great place to engage in the British car hobby! If you find BCF a beneficial community, please consider supporting our efforts with a subscription.
There are some perks with a member upgrade!**Upgrade Now**
(PS: Subscribers don't see this gawd-aweful banner
Hey - did you know if you click on the title of a thread it will take you to the first unread post since you last visited that thread?
but were afraid to ask: 
STOP!! Never post your email address in open forums. Bots can "harvest" your email! If you must share your email use a Private Message or use the 
smilie in place of the real @
Pretty Please - add it to our Events forum(s) and add to the calendar! >> 
TR2/3/3A epoxy primer
- Thread starter sp53
- Start date
Share this page
dklawson
Yoda
Offline
Follow the instructions on the primer's product data sheet. You will certainly be expected to remove existing rust, sand the surface with a specified grit of paper, and clean the surface with a prep solvent. The data sheet will specify how many coats to apply. Expect at least two. The epoxy may fill very tiny voids but it will not take the place of traditional fillers for larger areas. High-build primer on top of the epoxy and filler will take care of the rest. Remember the quality of the top coat will be reflected by the effort you put into the body prep and block sanding the primer(s).
PatGalvin
Jedi Warrior
Offline
Some epoxy products can't be used over acidic metal prep or rust removal products. So, check that first and be sure you're products are compatible. Clean metal is best for epoxy primer. Wash with detergent and rinse. Wipe with wax and grease remover, and then shoot it. Epoxy primer is great for sealing the metal and providing a base for other paint. It has a pretty long recoat time, so if you don't have body work to do, you can shoot your epoxy, let if flash for a couple hours and then shoot a polyester (high build) or urethane primer on top. This is called "wet on wet" and gives a great chemical bond. The polyester primers are like sprayable bondo and give a very nice high build that you can use to block sand. If your panel is already straight, then a few coats of urethane primer should do the trick.
Thanks you guys I really appreciate this. Hey Pat if I do not have the poly primer on hand can I put that on later, like a few days later, or do I need to put in when the surface of the metal is still bondable. I am painting the front clip (basically half the tub) and it is freshly sand blasted so the primer should stick. I was concerned about the white residue from the sand blasting, and I want to flip clip around so that I get primer up under and in those tight spots.
CJD
Yoda
Offline
High solids primer will go a long way to filling many of the pits. Really deep ones may take a couple coats with sanding in-between. And, the glazing compound is made for any too deep to fill with primer.
There are a lot of ways to clean the metal before painting. Read the data sheet on your primer and it will give you an idea if you have to pre-prep with an acid etchant. Most modern primers are self etching, so no prep needed. I clean with lacquer thinner and allow at least 30 minutes for the thinner to fully evaporate. Whatever you decide to clean with, allow ample time for all of it to evap befor spraying...otherwise it prevents the primer from adhering and it will lift later....if it doesn't fish-eye sooner.
There are a lot of ways to clean the metal before painting. Read the data sheet on your primer and it will give you an idea if you have to pre-prep with an acid etchant. Most modern primers are self etching, so no prep needed. I clean with lacquer thinner and allow at least 30 minutes for the thinner to fully evaporate. Whatever you decide to clean with, allow ample time for all of it to evap befor spraying...otherwise it prevents the primer from adhering and it will lift later....if it doesn't fish-eye sooner.
PatGalvin
Jedi Warrior
Offline
Regarding your poly primer question... For nearly all paints, you either need to apply them during their "open time/recoat window", when they are still not completely cured and can accept a wet coat of another paint and make a chemical bond. Or you need to wait for the complete cure (which is often very fast) and then sand (to create a rough tooth, for adhesion) and then spray. The open times are all over the board but often vary from just a couple hours to maybe 12 or 24 hours. Epoxy primer is the exception (in my experience). I have used SPI expoxy primer which has an open recoat window of about 5 days. I also use Kirker Enduro Prime which has an open time of at least a few days. The downside to these epoxy primers is that if you spray and need to sand, you need to wait at least a couple days and maybe up to 5 days because otherwise they will load the paper and make a big mess.
Poly primer has a lot of talc, like bondo. It will absorb moisture and is best dry sanded. Or wet sanded with a day or two of dry time. Urethane primer is a two part urethane product and can be wet sanded, briefly dried, and recoated. It does not absorb water and will seal a surface so you need not worry about rust. Many primers don't like outdoor exposure to UV light and will break down in UV. Epoxy typically isn't UV resistant and should not be exposed to the sun for long (weeks) periods of time. A couple days will just help it cure. Rattle can primers are all pretty porous and will absorb water and rust through.
Have fun painting. Epoxy primer can also be brushed on. That works great if you just want to seal your bare metal and come back to the repair later. Some people swear that epoxy primer is needed to seal the bare metal before filler is applied. There are diverse opinions about that - I put my filler on bare metal, per the directions on the can. Epoxy primer has a long pot life (in mild temps, you can mix and shoot it for a couple days). Other primers are more like 30 minutes (poly) to 1 hour (urethane).
Check our Southern Polyurethanes for Epoxy Primer. Barry is owner. He answers his phone all day and is a huge tech help. I used his clear on my car and thought it was a great product for a home paint job. Also very economical when compared to PPG and other big names. Kirker Enduro Prime is also good epoxy primer and you can buy that on line. It is very economical. Rumors have it that Eastwood's epoxy is actually Kirker, repackaged. I really like SPI's urethane primer. Put a couple coats of that on a nearly finished panel. Wait an hour. Apply guide coat, and sand to 400. It is great stuff.
Best of luck. That is the fun part!
Pat
Poly primer has a lot of talc, like bondo. It will absorb moisture and is best dry sanded. Or wet sanded with a day or two of dry time. Urethane primer is a two part urethane product and can be wet sanded, briefly dried, and recoated. It does not absorb water and will seal a surface so you need not worry about rust. Many primers don't like outdoor exposure to UV light and will break down in UV. Epoxy typically isn't UV resistant and should not be exposed to the sun for long (weeks) periods of time. A couple days will just help it cure. Rattle can primers are all pretty porous and will absorb water and rust through.
Have fun painting. Epoxy primer can also be brushed on. That works great if you just want to seal your bare metal and come back to the repair later. Some people swear that epoxy primer is needed to seal the bare metal before filler is applied. There are diverse opinions about that - I put my filler on bare metal, per the directions on the can. Epoxy primer has a long pot life (in mild temps, you can mix and shoot it for a couple days). Other primers are more like 30 minutes (poly) to 1 hour (urethane).
Check our Southern Polyurethanes for Epoxy Primer. Barry is owner. He answers his phone all day and is a huge tech help. I used his clear on my car and thought it was a great product for a home paint job. Also very economical when compared to PPG and other big names. Kirker Enduro Prime is also good epoxy primer and you can buy that on line. It is very economical. Rumors have it that Eastwood's epoxy is actually Kirker, repackaged. I really like SPI's urethane primer. Put a couple coats of that on a nearly finished panel. Wait an hour. Apply guide coat, and sand to 400. It is great stuff.
Best of luck. That is the fun part!
Pat
Attachments
D
DougF
Guest
Guest
Offline
Google Rust Defender. It's a one step fill/sealing primer. I'm using it on my TR3. I have seen several end results that turned out beautiful and have held up for years.
Well Pat I hope to get my hood to that point soon--- looks good. And yes for sure the block sanding and touching things up is a lot more fun than banging rust and old paint off. Have not done much yet, but what I have done is actually fun and rewarding. You have been a big help, much appreciated.
Steve
Steve