spar painting

[mdidomenico]

i've finished painting my boom, spreaders, and some other parts.  the mast is up next after the next batch of paint is delivered.  i thought i would write up what i did as a point of reference for others that might want to tackle the same project.

i pulled the mast, boom, and everything apart, all fittings removed
i then sanded everything using 40-80 grits using the combination of orbital and drum sanders to get back to bare alu
i then stepped up to 120 grit

i found that using an angle grinder definitely took the layers of paint off faster, but dust collection was a problem and i found that the angle grinder scratched the aluminum too heavily even with 80-grit flap wheels.  it turns out the primer goes on thick enough that these scratches didn't matter

i choose to go with Totalboat products.  I have zero experience but they were the only vendor that had an entire line of products to accomplish this task and i was afraid if i tried to mix products from different vendors something would go wrong.  at least in this case all the mixtures should be compatible and anything that goes wrong can only be blamed on the user

Here's what i ordered to do the boom, spreaders, masthead, and sheave separator plates

(1) quart alu etch
(1) quart surface dewaxer
(1) quart primer thinner 200
(1) quart brushing thinner 100
(2) quart alu barrier coat 2-part epoxy primer
(2) quart wetedge top coat
assorted rollers, cups, etc.

i learned the hard way to get rollers designed for solvents.  the non-solvent cheapies from lowes end up swelling and breaking apart after a bit.  also solo cups or the cheap plastic cups from shoprite end up melting

the primer and topcoat i used about 1-1/2 quarts total for 3 coats of each and i still have 1/2 quart left of each.  the thinners not much.  the quart of each thinner i still have quite a bit leftover.  i expect a gallon can of primer and topcoat will do the entire mast.

i also ordered their ecosolvent for cleaning my tools.  it works well, but smells horrible and it lingers in the air and your nose.  seeing how little of the brushing thinner i used, i could probably have just used that instead (which totalboat says you can do)

repainting steps

1 wash all the bare alu parts with water and abrade with scotch brite pads (i used purple ones)

2 etch the alu with the acid wash.  the acid wash was much thinner then i expected.  i thought it would have a little gel consistency to it, but it's actually like water.  the quart goes a long way.  i just brushed it on

be careful, i wore sandals and got a little on my foot, it mildly burns.  i lucked out with it literally being a drop, but hey it's acid be careful

3 wash alu parts with plenty of water.  totalboat says the water should bead up.  the alu definitely got a little brighter

4 dry alu parts with a towel let air dry until no moisture is seen

5 wipe alu parts down with the dewaxer.  wait for it to fully evaporate and then wait a little longer.  there was a spot on the boom that hadn't fully evaporated, even though i could see no shine from the liquid.  when i went to apply the primer and i could tell it wasn't sticking.  i had to sand and redo from step 1 a small section

6 apply the alu barrier primer.  the mix comes in two cans, the paint part of the mix needs to be shaken fairly hard to loosen the solids and it gets fairly thick after you do this.  if it isn't slightly thicker then latex paint you didn't shake it hard enough.  i would shake the paint and then use three 30ml syringes to transfer the paint, the hardner, and the thinner from their cans to a mixing pot in the appropriate ratios.  i mixed into 120ml batches with only a little primer puddle and whatever was soaked into the roller

7 apply at least three coats.  the primer rolls on pretty easy and drys within 4-6hrs (it was 80F and 75% hum when i did it, inside a garage)  you have to recoat within a window otherwise you have to abrade the surface (read the can)

8 the primer will end up looking scalely or orange peely.  after the primer dried i sanded with 120-grit.  the primer sands easily, be careful i went through the primer back to bare alu in a couple spots when the sander edged up.  totalboat recommends 80-grit, but that seemed to aggressive to me.

9 i followed the same mixing procedure with the topcoat paint, measure out paint and thinner using syringes, apply at least three coats
the first coat of top coat will not hide the primer, the second coat should, and each successive coat will get glossier and glossier

i had a little bit of trouble with the top coating, here's what i learned

1 the totalboat wetedge really doesn't need much thinner.  the first and second coat of topcoat heavily ran in places.  i had to spot sand and reapply a few times.  also if you add too much thinner the paint takes forever to dry.  it's supposed to be sandable dry within 16hrs, my first coat took three days.  when i backed off the thinner i could do successive coats over successive days

2 the foam rollers have a tendency to drop too much paint at their edges.  i found that on occasion when i rolled out the paint i'd get roller edge lines, if i caught it, its easy to roll out, but if the paint dries you have to sand and recoat that section.  this is probably just a technique issue for me

3 it's not clear whether tipping would have helped me.  i tended to over work the paint with the roller and my topcoat has some orange peel and wavyiness to it.  i tried to patch up a couple of sections with a brush before things dried and that just made it worse.  my understanding is the paint needs to flow pretty freely for tipping, but that required more thinner then i needed which made the paint run.  just using a roller seemed fine and the paint is glossy.  the orange peel effect i see in spots i think is just my technique not the paint.  the parts i didn't exhibit OCD and over work with the roller are in fact mirror glossy

4 they recommend abrading with 220-grit between coats.  i found the 220-grit gummed up the paper to easily.  hand sanding with a light touch with 120-grit was better

5 there were a couple of sections where i didn't get the primer sanded down smooth enough and the texture teleported through.  it lessened with each coat, but i should have been more careful.  (hint dont do this in a dark/shadowy garage)

so the end result.

is it a pro quality job, absolutely not.  would it have come out better had i sprayed.  perhaps, but i don't have the equipment to do that.  (it's oil/epoxy based, special ppe needed) would a pro job have given me a mirror finish, yes, but i don't care.  2/3rd of the spars aren't even seen closeup most of the time.  from 10ft away you can't tell

would i do the job over again or sub it to a yard.  i'd still do it myself.  though i'd probably have the yard sandblast the old paint rather then slave over it with an orbital sander.  taking apart all the spar fittings is a pain and laborious and the painting is as well, but it wasn't bad enough that i'd pay someone else

would i use totalboat again.  yes.  i can't say from a paint perspective because i have no reference and we'll see how it holds up over time.  but i like that its a single source for all the products i needed.  i've also contacted their support a few times and they've been responsive and helpful, which is always nice

i'm happy to answer any questions, but keep in mind, i'm no pro and this isn't a tutorial.  i'll circle back after i do the mast in a couple weeks