G Atsma

First off, don't use a grinder. Use an orbital polisher. And then don't bear down too hard. Just watch carefully what you are doing.

orange88ls1s-dime

Sponge your epoxy on so you don't have to clean your paint gun then spray some evercoat slicksand on in 2 liberal applications then start with 180 and a long board alternating direction frequently working your way up to 320 or 400 before you apply your top coat
this stuff takes time but if you go through the steps you will end up with a good surface that any paint would be happily applied to

badmfkr

iTrader: (4)

actually I used the abrasive grinder wheel suggested earlier mainly to remove the old cracked vinyl, I barely applied pressure.pronablly should have used a heat gun and razor or scraper.

I don't have a orbital polisher really wasn't planning on getting to involved w/ buying a bunch of paint tools. I do have a el cheapo car wax buffer w/ sheepsskin pad. can't I just use green scotbrite to minimize the grinder swirls then prime?
Thanks

So I have alot of smoothing before primer.

I'm new to painting please excuse my lack of understanding paint terminology,

when you say "sponge your epoxy on" I assume you literally mean use a sponge brush? I don't have a paint gun, the man that painted my bumper and fender (years ago) told me the boat was painted acrylic enamel w/ a brush and roller from the factory which is actually true so my plan was to use a decent $10 brush.

excellent tips on sanding the primer gradually decreaseing grit.

I was able to clean w/ acetone then re glue in between the panels w/ 3M 5200, bad is the wind blew dirt specs on lower bead.

the smooth aluminun around windows can I get away w/ just a scuff w/ green scotbright pad?

I also smeared JB cold weld over the seams on the door I fabbed. I used a sandpaper type wheel on the grinder to remove surface rust from the then smooth aluiminun that now has even deeper swirls than the side panels.

look closely at the door lower panels oxidation what is suggested for it's removal?
Thanks for advice

orange88ls1s-dime

Once it's all one colour the surface swirls will be minimized but if you've ever seen a repainted counterweight on a forklift that's what keeps coming to mind
if you go through the motions I bet that would be the nicest boat on the water next spring

badmfkr

iTrader: (4)

yes I'm willing to put the time in, to do the correct method so it will look good.

according to the tech specs on my primer

?1. applications temps can't be lower than 50 degrees fahrenheit, I assume this is outside temp. or temp of metal is it like cooking a chicken and checking it's temp w/ a themonitor?
?2.is applications temp. different from curing temp.? like can I prime on a day where temp. won't drop below 50 but the following day could drop below the 50 will this ruin the cure or just slow it down?
right now it's getting colder/wetter, I hope I can pick a none raining day w/ temps above 50 however

?3.is there a time limit after primer that the top coat must be applied?

https://www.jamestowndistributors.co...t.do?pid=98144

G Atsma

Basically 50 degrees is the minimum operating temp. If the material being worked with has been outside, it will also be 50. Curing should also be 50 or over.

JoshHefnerX

If you're gonna paint that aluminum you want to use a zinc based primer right ontop of the aluminum. Zinc was designed for adhesion to zinc. Use something like this - You may be able to find it locally at a boat shop but the stuff is getting expensive and hard to find as it's somewhat hazardous to breath in.

badmfkr

iTrader: (4)

you are correct about the zinc primer however it's not recommended now mainly because of the tree huggers.


https://www.jamestowndistributors.co....do?pid=336169
explaination here.Why Do I Need to Etch My Aluminum Boat Before Priming and Painting?

Getting primer or paint to stick to aluminum is very difficult, and it's a tedious process that typically entails sanding with very coarse sandpaper or blasting down to shiny, bright metal followed by priming with a specialty primer. The zinc chromate primers commonly used in the past are expensive, and less widely available now due to environmental restrictions. It's also not good for painting underwater metals, because zinc is the stuff of sacrificial anodes!

You can certainly still get excellent results with primer and paint, but the secret lies in etching the surface with the right product. Compare TotalBoat Aluminum Etch Wash to Alodine or Alumiprep 33. Our phosphoric acid-based etching wash is easy to use and works fast to create the toothed surface required for epoxy primer or paint to bond effectively and durably
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I'm also priming and painting the lower transome which is underwater.

update on the swirl marks.
I have green scotbright pads but can't find them so I used a kitchen scrub sponge and was able to significantly reduce the swirl marks.
can I step up to the red scotbright pad to further reduce the swirls?

is TotalBoat Aluminum Etch Wash basically acetone?

I attempted to trace the decal but the plastic I used was a little flimsy when I attempted to transfer w/ exacto razor knife to a cardboard for stencil.
next I'll attempt to use butchers paper w/ a gravestone pencil rub, this decal maybe hard to duplicate so any suggestions would be a huge help.

Thanks Guy's for the surport

orange88ls1s-dime

Yes just use acetone but make sure you do minutes before you spray you first coat of product as aluminum produces an oxide film within hours given the right conditions
I'd say go to John Deere and get some zinc rich epoxy as agricultural doesn't seem to have as strict of rules as automotive but I haven't bought primer from them in 2 years so who knows if they haven't screwed that one up too

badmfkr

iTrader: (4)

update on the swirl marks.
I have green scotbright pads but can't find them so I used a kitchen scrub sponge and was able to significantly reduce the swirl marks.
can I step up to the red scotbright pad to further reduce the swirls?

jlcustomz

Hey, hadn't looked in on this in a while. Here's a little mixed jumble of thoughts.
Epoxy is the preferred primer to put on raw aluminum. 80 grit from a da sander is typical recommendation for rough enough to bite good. you want a little rough & sanding should be fresh before primer as aluminum starts oxidizing instantly. A little 5" dewalt sander from home depot has da(random orbital) type motion. Scraping would have easily gouged the hell out of aluminum, worse to try & smooth out. Remember than aluminum isn't much harder than some paints. Quit playing with scuffing pads & sand it. You can get tiny rolloc type discs for a Dremel. Epoxies do have their minimum temps to stay above. My SPI primer for example needs to stay above 65 degrees for 24 hours or it may never harden properly (FAIL). Primers would take care of your remaining stripping scratches after sanding before & after them, you're painting, not polishing it.
I used one of these damn etching primers under 2 k primer on aluminum before, had a few bubbles. Epoxy after rougher sanding from here on for me.

At work I have used Sherwin Williams pro multi surface acrylic waterbourne straight on fresh sanded raw aluminum for storefront window posts, no primer called for per instructions for aluminum & many other surfaces. Less than $40 per gallon at my contractor price. Very fast drying in proper conditions, I have sanded in less than 30 minutes sitting in sun. Not as hard as an automotive urethane or enamel paint, would be harder to clean. Just mentioning it since you are not an experienced painter with fancy paint tools & the better paint stuff like epoxy is summer outdoor stuff, not winter.

badmfkr

iTrader: (4)

Yes I have epoxy primer I’ve been told (on the boat/design forum) the total boat primer linked

Here https://www.jamestowndistributors.co....do?pid=336169 is just a rebadged product.this primer should be decent even if rebadged because Jamestown is a reputable co.

Dam I just read this epoxy needs 10% reducer (or do I misread/understand) I maybe over my head.



I was actually planning to try to primer this Monday around 9am the high temp of the day will be 50 degree’s however the following Tuesday & Wednesdays will be right at 40.



My primers application is above 50 degrees so I’m assuming Tuesday/ Wensdays will ruin the cure? This side of vessel is exposed to direct sunlight though out most of day however the plan was to apply primer then cover w/ trap to prevent tree leaves/flys sticking to primer (should have covered the seams glue w/ tarp to prevent the wind blowing dirt specs on glue).



I traced the decal out w/ thin plastic but was unable to transfer w/ exacto knife to thick paper (old cereal box) for stencil (plastic was to flimsy)

Can I duplicate the decal w/ butchers paper gravestone rub?

still want to know if a red scotbrite pad which is more abrasive than a green will reduce swirls? the plan was to prepare/stripe/expose the majority of the panels then 30 minutes prior to priming remove the new oxidation of aluminum w/ harsher red pad. I'll have to be quick w/ a 4 hour pot life.

edit: lastly for right now I'm concerned about the the overcoat window like how long can I wait to apply top coat of acrylic enamel? was planning on leaving the panels exposed to direct sunlight for a few weeks which now has proballey stretched to next spring.

COTCHBRITE GRIT CHART (courtesy of Charlest) back to top
3M Scotch Brite Nylon Pads:
7445 - White pad, called Light Duty Cleansing - (1000) 1200-1500 grit
7448 - Light Grey, called Ultra Fine Hand - (600-800) 800 grit.
6448 - Green (?), called Light Duty Hand Pad - (600) 600 grit
7447 - Maroon pad, called General Purpose Hand - (320-400) 320 grit
6444 - Brown pad, called Extra Duty Hand - (280-320) 240 grit
7446 - Dark Grey pad, called Blending Pad (180-220) 150 grit
7440 - Tan pad, called Heavy Duty Hand Pad - (120-150) 60(?)
Green Scotch Brite is available EVERYWHERE. It's 600 grit.
Blue Scotch-Brite is considered to be about 1000 grit.
(The value inside the parentheses is directly from 3M.)
3M Chart

Thanks for advice

jlcustomz

Epoxy's can all be different. This type is more of a fast dry, less than perfect conditions type stuff as it's meant to be brushed or rolled on in a wide temp range.. If you paint asap in the morning when warm enough & let the sun hit it, It'll probably be good for full cure.. Induction time means let sit after mixing before using.This makes it more user friendly to put it simply. Reducer helps it to flow out better. Epoxy can be thick & will cover these swirl marks that I think you're worrying too much about. Rolled on epoxy will probably have a fair amount of texture that will make you feel silly about trying to finish the metal smoother. You'll soon likely see what I mean.
The epoxy I'm used to needs a few days before filler or paint & has a 7 day window average to not need sanding for other product adhesion. It is also better with mine if it sits a few months to give it a thin respray for maximum adhesion as nothing sticks better to epoxy than epoxy.In automotive use , it get's thinned for use as a sealer coat. But that's not your stuff. Supplier should be able to answer a few questions. If it sits till spring , a sand & recoat may be better, but I can't say if it's needed.
Read their Q & A & tech data on their site under more info..They are trying to sell you on the etch wash first, which is probably the same acid in ac coil cleaner.They are saying do 4 or 5 coats, which is quite a bit, I say if ya can't paint it now, get it covered with or without reducer , sand & recoat in spring. Best to use their reducer to avoid problems & for best self leveling..

badmfkr

iTrader: (4)

I have a small window w/ weather temps on none rainy day so hopefully I can get some primer applied however

I’m confused on the mixing ratio easy marked cups, are there ounce markings?

The primer I have is a three to one ratio. I want to start mixing half of what I have so I need to measure.

The large container has .75 (3/4) of a quart I’m thinking is equivalent to 24ounces.

The small catalysts’ (hardener) container has .25 (1/4) of a quart I’m thinking is equivalent to 8ounces.

I looked at a paint measuring cup at walmart.

Please excuse my ignorance but I don’t see ounces on the markings.

Thanks for tips on mix cups

G Atsma

12oz primer, 4oz hardener.... half of what you have....

badmfkr

iTrader: (4)

G atsma I hope you and you'res didn't get burned in the latest disaster.

I know how to divide by 2.

I watched like 4 videos this kindof explained the ratios on the cups

1. find the ratio on top of cup
2. the digit to the left is the product (primer) is this digit in ounces?
3. the next digit is the hardener if #1 is ounces then #2 must also be ounces, not sure what the third digit is.

once I'm confident in how to mearsure I think I'll start w/ 25% instead of 50%
32OZ will cover 100 square feet the rear and side panels are a fraction of 100 square

Thanks for tips on mix cups

edit: seams to me when initially pouring the contents into the small cup this small cup should be inside a larger cup to capture the wasted contents. just my observation.

edit2: I was planning on acrylic enamel paint for top coat .this https://www.google.com/search?sa=X&t...38377515115425



However I prefer a flat, just found out from Wiki that acrylic enamel paint is a gloss shiny finish.