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Polishing an old fiberglass boat.

Discussion in 'Technical Discussion' started by Bahma, Feb 11, 2017.

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  1. Bahma

    Bahma Member

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    My 1982 42 ft Bertram has quite a serious bloom or dull surface, I am hoping you can offer advice as to the best and most efficient way to restore the original luster.

    It is not scratched or otherwise damaged.

    A friend suggested I wash it with an acid first, ......is this a good idea?, if so, which acid, and how do I protect the chrome and stainless fittings.

    I do have various compounds which I have used, with little sucess, I'm hoping that if the surface is cleaned by the acid wash, the compounds will be more effective.

    Very many thanks,

    Vir Ipse.
  2. praetorian47

    praetorian47 Member

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    I've had extremely good luck with 3m Imperial Compound and a wool pad on a rotary to bring back gelcoat. It's a one step and does a really good job. If it's bad, you may try two passes. If that doesn't do it, there are stronger abrasives and even wet sanding but that's beyond my experience.
  3. Beau

    Beau Senior Member

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    Agree. The 3M multistep process is excellent . Go to their website for video instructions
  4. Bahma

    Bahma Member

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    Thanks for the advice, I've watched several utube vudeos showing the 3M technique.

    I'm at present, varnishing the handrails, which were zeriously neglected by the PO.

    The 'glass is next on the list....I do have 3M polishing compounds on habd as well as some products by Surehold....they came highly recommended, I have not yet tried them.

    I'll let you know how it goes.... there's much to polish.

    Thank you again
  5. Capt J

    Capt J Senior Member

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    The Easiest way is to hire a professional. 3M makes good compounds, you're going to have to find what grit works and then work your way finer, then wax......I perfect either collinite or rejex over 3M's waxes.
  6. CSkipR

    CSkipR Member

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    If your going to tackle this job be prepared it will take some time and its not easy. Best to hire a professional but if you want to do it here's what I suggest. Would not recommend an acid wash. Pick a spot and try a heavy duty compound and see if it brings that spot back to life. If not start with wet sanding using 600 grit, then 1000 and then 2000 followed by a good waxing. Its a process.
  7. Beau

    Beau Senior Member

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    If you have never done it before, be very cautious with wet sanding, particularly if you choose to use a machine of any kind.

    Start in an obscure spot - depending on the thickness of your gelcoat, you can sand right thru it. probably unlikely on a Bert? Also watch out for gouging if you are using a machine
  8. ksbguy

    ksbguy Member

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    There's no shortcut out of this and it's at a minimum a three step process. You first need to compound to remove oxidation and it'll look shiny after this but there are lots of compound scratches/swirl marks which will cause UV light to be absorbed instead of reflected. This results in rapid deterioration of the gelcoat no matter what wax/polymer you put on top. The next step is to polish the gelcoat to remove scratches created by the compounding. You want as much reflection as possible and the wax/polymer has nothing to do with the shine, it's just a protective coating.

    I use Presta products which contain diminishing abrasives with no fillers. The ultra cutting creme followed up by ultra polish will get you really nice results with good reflection. Depending on how oxidized your hull is you may need to use a more aggressive compound.

    Each stage requires a different pad. You can't use a compound pad with a polish or vice versa, it won't work.

    There's also the skill of using a buffer which takes some time to learn but you can get decent results watching some videos and just remember to keep the buffer moving and use the recommended speed for the product you're using. It's normally lower speed with more pressure then you increase the speed and decrease the pressure.

    The last stage is to apply a polymer or ceramic type coating. Waxes are a waste of time (maybe okay bellow the rub rail in northern states) because the sun heats up the wax and the impurities in the air ( acid rain with soot and everything else)becomes trapped in the wax. I've tried a lot for all for over 15 years and so far the ceramic coatings seem to work the best. I used to use Rejex but that also requires stripping after a few months but it is better than wax.
  9. praetorian47

    praetorian47 Member

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    I agree with the ceramic coatings, but they are expensive. What product do you use?

    I use CQuartz on my boat. The new boat will probably take 300ml or more, and this is the second year they've been used. I found the first application takes a lot of product on gelcoat because it's so porous.

    I use their UK formula because I wax Ina heated building during the winter and it's now overly warm. I then top with Reload. Over the summer, I use their hydro2 spray on/ rinse off every month.

    I use their Essence compound where I can because it has CQuartz/ silica fillers that add protection and serious shine.
  10. ksbguy

    ksbguy Member

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    I tried Marine31 captains coating with UV 50 and it's been working pretty good but it requires a bit of elbow grease to level the coating - dries very quick. On about 8 months now and the dirt still just washes off. An 8oz bottle (~235ml) is about $50 so much cheaper than the CQuartz.


    How's the CQuartz to apply on gelcoat?
  11. praetorian47

    praetorian47 Member

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    It's not bad to apply, as long as you have good light. I find it's a 2 person job with one person looking on at a different angle to ensure no streaking. Not cheap though.
    I find Reload to be the best product I've ever used on my vinyl windows though.
  12. ksbguy

    ksbguy Member

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    Thanks. I'll have to try the reload on the vinyl windows.

    How long does the CQuartz last for you before it starts to loose shine?
  13. praetorian47

    praetorian47 Member

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    Great question. I don't actually know. I applied last winter on my last boat and it was still going strong when I sold the boat in November. The boat I bought was done last winter with CQuartz too and it's still shiny. I can see where the previous owner didn't buff it out well (where he was learning) and you can see the brush strokes under the right light (and only up close).

    I applied it first in the winter of 2015 to my hardtop because no wax would last. I found it lasted the season with s little effort. I started washing once a month with their reset shampoo. It really takes the contaminants off, soot, whatever. You think the hull is clean, even after washing and this stuff comes away dirty and you see it shine more.

    I got my wash process down pretty good. I bought s tiny pressure washer (ar blue 118) and got a foam cannon for it. I rinse then foam a side, agitate with cloth then rinse. I'd then dry the boat. I could do my 466 carver in about 40 minutes, including drying and putting everything away. The boat had more shine than any other at my marina.

    On my Ocean, I won't be able to dry the bridge - too high, so I bought a deionizer so I can get a spot free rinse. No idea what it will cost in resin for it over the season, but I figure around $400.

    I should point out that I didn't really like the carpro glass treatment. I found it left streaks. I use a glass coating from sea-Shield.com. Prep is a bit of work but worth it. Glass stays clean.

    For nonskid, I use Aurora sure step. If you use it, follow their directions and only use their products to prep clean. 2coats last all season.
  14. Capt J

    Capt J Senior Member

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    Why don't you just dry the boat with a shurhold chamois mop?
  15. praetorian47

    praetorian47 Member

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    I found it left streaks and water behind that left spots. I use waffle weave towels or Microfiber Madness Dry Me Crazy towels (especially for vinyl windows) they're thirsty and super soft, they won't scratch anything.
  16. ksbguy

    ksbguy Member

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    Thanks, I'm running a 444 right now.

    I'll stay away from the carpro...

    I use distilled water for a final rinse. If you put a water softner infront of it and reduce the water pressure it'll last a lot longer. Do you know what your TDS is there? Mine is only about 100 so the deionizer lasts entire season and more on one resin refill. I use the "on the go" deionizer and softner, the smallest ones for few hundred bucks each... I never dry it and there are no water spots.
  17. praetorian47

    praetorian47 Member

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    What brand do you have? I get my water straight from Georgian Bay and then run it through a few filters. It's clean but probably harder than yours.
  18. ksbguy

    ksbguy Member

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    Sorry, I meant deionized water on post #16 not distilled :)

    "On the go" it's called.

    Deionizer:

    https://www.portablewaterdi.com/

    Softner:

    http://www.portablewatersoftener.com/
  19. praetorian47

    praetorian47 Member

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    I've looked at that brand before. It does appear to be the most economical.
    I'm going to look for a mounting location on the boat to install it. I want it and the pressure washer mounted inside somewhere and just have a quick release hose bib to connect the hose and wash. I like my boat clean, but I don't want to spend any more time than needed doing it!
  20. ksbguy

    ksbguy Member

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    I hear you there. I just leave it on the dock right now. You also want a bypass between the softner and the deionizer so you can just flip some valves until the final rinse. I always leave the softner (cheap, just recharge with salt) connected and on the final rinse right now I need to disconnect hoses to put the deionizer inline which is a little bit of a pain. I couldn't mount it anywhere on mine without some fiberglass modifications for it to be hidden because they need to be upright - these resin beds don't work horizontally.

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