Grind/Clean/prime then paint vinyl and aluminum

Discussion in 'Boatbuilding' started by the brain, Dec 21, 2017.

  1. the brain
    Joined: Sep 2016
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    the brain Senior Member

    Grind/Clean/prime then paint vinale and aluminum


    Inbetween factory aluminum sheets seams is dryed,cracked

    I have several none harsh discs to remove glue, plastic

    Adhesive.

    1.what exacty is this stuff?caulk?

    2.what to replace w/.?


    Will start glue removal w/ this disc. Avanti Pro 4-1/2 in. x 5/8 in. -11 in. Non-Woven Quick-Strip Disc-PNW045STRB01G - The Home Depot https://www.homedepot.com/p/Avanti-Pro-4-1-2-in-x-5-8-in-11-in-Non-Woven-Quick-Strip-Disc-PNW045STRB01G/202830907



    Here’s my plan the main objective being prime exposed transom skin

    w/ a two part expocy primer.w/ this

    TotalBoat Aluminum Boat Barrier Coat Epoxy Primer https://www.jamestowndistributors.com/userportal/product.do?process=checkout&part=498240


    then scuff old paint and repaint from gunwales an up color will be medium dark grey.
    TotalBoat Aluminum Boat Topside Paint https://www.jamestowndistributors.com/userportal/show_product.do?pid=336274&familyName=TotalBoat+Aluminum+Boat+Topside+Paint#

    Whole hut will be painted including alloy window frames all grey


    TB
     

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    Last edited: Dec 21, 2017
  2. PAR
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    PAR Yacht Designer/Builder

    That disk will very quickly fill with melted goo if run at the typical 1,200+ RPM's of a drill. You may have luck if you can run it much slower, though I bet it'll still clog up quickly. The better approuch may be to take a fresh razor to the edge of the seam, sliding along the sheet, slicing it off. Make the first cut perpendicular to the seam, cutting through the goo. The next pass slice it off the surface, maybe with a sharpened putty knife. There'll still be a bit remaining, but this is where the abrasives can finish it up. I wouldn't use a disk, as these will still leave a little along the edge and it's too easy to "lift" a seam edge with a rotary tool. Consider a multi-tool with a sander attachment. You go through some paper, but it'll do a neater job, without the potential of lifting a seam.

    If you expose raw aluminum, you should consider an etching primer (like TotalBoat Aluminum Boat Etch Wash), though for a trailer borne boat, the automotive etching primers will do just as well, for less money. The key is prep, as with all painting. Raw aluminum needs a good "tooth" and 220 grit and wash down with denatured alcohol will do, as will an etch wash or etching primer. Previously coated surfaces need the same thing, except for the etching requirement.

    TotalBoat Aluminum Topside is a water borne polyurethane. TotalBoat Aluminum Boat Barrier Coat is an epoxy. The barrier coat can be used without an etch, but the aluminum should be sanded and cleaned literally minutes before you apply the barrier coat. Given the areas you'll need to paint, you should do the etch, other wise you'll have to clean and primer as you go, which is inconvenient to say the least.
     
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  3. the brain
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    the brain Senior Member

    excellent advice

    can I scuff old paint w/ 3m green scrotbrite shrubbier and repaint? w/out priming, see I was only planning on priming exposed bare aluminum transom skin and pod. side piece & backdoor of hut.
     
  4. the brain
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    the brain Senior Member

    this glue is thin & way to hard to cut w/ knife I tryed and was only able to remove about a 1" to expose the seam.

    I would like to smear a new layer of glue/goo. over this cracked seams then paint.

    haven't tried new grinder wheel yet.

    I have a dremel4k w/a small flapwheel it could prodablly fit into the corner of gunwhale,new plastic disc will grind out the vertical seams.

    first I get out heat gun and melt goo. maybe
     
  5. PAR
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    PAR Yacht Designer/Builder

    The problem with heat and chemicals, which seem logical is they do work, but they also seep under the seam loosening things other than what you want to remove.

    I've cleaned thousands of feet of seams over the years and rotary disks and flap wheels do work, but they leave a small line just above the seam, which needs to be removed too, so I've all but abandoned them, except for bulk removal efforts. If you're looking to just clean up the cracked and split stuff and recover with some more goo, an orbital sander is good for this. Work the disk so it rotates off the seam, so you don't catch and edge. This will taper the existing goo and offer a place for a thin smear of new to cover the old stuff.

    For seams like yours, I like to use a hot knife, which will slice right through that goo. I usually have a MAPP gas torch sitting on a stand and I heat the utility knife blade until dull red, then directly to the work, cutting as much as you can while it's hot. You'll feel it start to drag when it cools too much, so reheat it. On a big job, I'll have two knives, one in the heat, while I work the seams with the other. Try this technique before you start grinding with a flap wheel or disk, as these remove more than goo, but also a considerable amount of aluminum, which is thin so not much to give up. I like neat seams, so I'd be looking for a clean line at the joints, but it's your boat and if you can knock it down enough, you can smear a new line of goo over it. Consider taping off below (1/16" or so) below the seam line, so the new goo will have a nice clean edge, not the smear of caulk line, everyone has around their bathroom sink.
     
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  6. Barry
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    Barry Senior Member

    Is it possible to use an extremely small abrasive shot blaster to blast the mastic/caulk out of the joint. Not sure if a person would use sand or maybe walnut shells.
    I have seen this used on seams between sheet steel but would be extremely conscious of abrading the thin aluminum. Perhaps with walnut shells or corn cob husks, the caulking
    might erode without any impact to the aluminum;

    Small gravity feed blasters can be rented or buy one if you have a compressor very cheap.
    You would not want to do any large unsupported thin sheet panels as under the right conditions you can warp the sheet.
    Air compressor wise, you might need 10-15 cfm at 60 - 90 psi
    You can buy cheap gravity fed guns without hose for maybe 50 bucks
     
  7. upchurchmr
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    upchurchmr Senior Member

    First you need to learn to spell vinyl.
     
  8. the brain
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    the brain Senior Member

    excellent advice I don't have a MAPP gas torch considering a Bernzomatic Torch https://www.amazon.com/dp/B00008ZA09?tag=viglink20380-20
    https://www.amazon.com/dp/B00O4D1CUG?tag=viglink20380-20

    1.would a green Scotbrite abrasive srub sponge be able to smoothout the cracked goo?

    2.what product to smear over sanded cracked goo?
    thanks TB
     
  9. PAR
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    PAR Yacht Designer/Builder

    ScotchBrite isn't aggressive enough to do more than polish the hardened goo. MAPP gas can be used in any propane torch and it's hotter, which is why I use it. I have one of those Bernzomatic torch heads probably 30 years old, but still works. Whatever you apply over the cracked goo, will likely permit the cracks to "print through" in time.
     
  10. the brain
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    the brain Senior Member

    update I tryed the plastic somewhat abrasive wheel
    1 it was to thick to fit inbeteween the seam to grind out the dryed caulk
    2 it was very abrasive on the allready thin gauge .100 aluminum.

    note the factory enclosure is kindof flimsy like when hull is being stressed I can hear/feel the top an/side twist and creek.

    I'm thinking the enclosure needs to flex as doe's the hull and it was designed to flex otherwise it would snap/break..

    I'd like to mix the full contents of my primer/2 part expoxy so I've been planning what can be painted after the 1.primary part (transome exposed aluminum)
    2,like the outside door/wall enclosure/transome cap/gunnels

    when I painted the floor and a 2' x2' box w/ the rustolium I used the whole quart becasue the paint was so thick.
    I have the quart size primer curious of how much I can cover?

    next I try dremel w/ small flapwheel. final method of dry cracked caulk removal white roloc wheel.

    heres the plan scuff w/scotbrite clean w/ TSP substitute prime then paint
    https://www.walmart.com/ip/Klean-St...035&wl11=local&wl12=17208811&wl13=930&veh=sem

    Thanks TB
     
    Last edited: Jan 27, 2018
  11. the brain
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    the brain Senior Member

    The roloc wheel wasn't able to go deep into seam.

    will heatup and try the razor blade/sharp putty splattuler.

    Thinking the second image that brown cracked vinly will be completely roloced.

    TB
     

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    Last edited: Feb 28, 2018
  12. pauloman
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    pauloman Epoxy Vendor

    for prime or topcoat google aluthane - a mositure cured urethane - aluminum based paint
     
  13. the brain
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    the brain Senior Member

    actualley I already have the aluiminum primer from jamestowne.

    what I need a recommendation on is what material and include brand name to replace or basicalley smear directly over the dryed up stuff that's inbetween the seans?

    I'm about to use my rubber brissle rolock wheel w/ the propor air die grinder wheel it's RPM 25K ten times what my electric drill could turn wheel. to grind the mess out even then I will need to smear something as a replacement.

    also notice the big brown vilye sticker can it be scuffed and primed or musrt it be completely smoothed off?
     
  14. PAR
    Joined: Nov 2003
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    PAR Yacht Designer/Builder

    The nice thing about high speed rotary tools is they can remove things fast. The bad thing about high speed rotary tools is, they can remove things fast, likely much faster then you're prepared for.

    You can scuff the vinyl sticker and prep for paint, though yeah, of course it's going to show, it's standing proud of the surface a mil or two. If you can feel it with your hand or if primered over and "blocked" down it shows it's edges, yeah, you can guarantee the finish with have the remains of the outline in it.

    Jamestown's aluminum paint isn't remotely close to the product Paul above mentions. The Jamestown product is just a rebadged thing, a new label put on another manufactures product. I think their aluminum primmer is actually an Interlux product.

    The goo between the plates is probably butyl tape or, straight butyl applied with a gun. This is still available if you want, though has to a great degree been replaced with polyurethanes.
     

  15. the brain
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    the brain Senior Member

    please suggest a polyurethanes.

    i have only purchased the primer not picked top coat
     
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