Forums > Sailing General

Deck repair advice

Reply
Created by Microbe 3 months ago, 25 Sep 2020
Microbe
WA, 91 posts
25 Sep 2020 2:27PM
Thumbs Up

Hi, yet another deck repair and painting thread.

I'm planning to refresh my tired old deck with kiwi-grip.

Current deck condition is chalky paint over molded non-skid. There's plenty of cracks in the surface. What do I need to do to prep before applying Kiwi-grip. Should I dremel out the cracks and fill? Or would scraping and sanding be sufficient?

TIA

r13
NSW, 625 posts
25 Sep 2020 5:31PM
Thumbs Up

Cripes - what is the yacht design?

That blue paint looks like it was laid on with a trowel - and this is probably part of the cracking problem due to too thick a coating and possibly insufficient surface cleaning by the original applicator - if this was you apologies am not trying to be negative - the hole in the paint in the middle upper 1/3 of the photo looks very unexpected - mind you all the cracks do also. The apparent silicon or polyurethane sealant along the cabin and gunwale corners is also unexpected. The cabin side and gunwale appear to be 2 pack polyurethane paint coated over the original gelcoat. Is this correct? On the gunwale this coating seems like it could be refurbished also - but not of the same priority as the blue.

How old is the blue paint and do you know what exact type it was? Probably a single pack non skid deck paint?

If you try and Dremel out all the cracks in the paint you surely will be doing that till the end of time, and end up with a surface like a badly cracked very dry river bed.......strongly suggest don't do this.

Rather and sorry to say imho all the blue paint and sealant needs to be completely removed, to get back to the moulded deck including the non-skid original surface, and start from there. The sealant will probably be easily removed by digging it out at a cabin corner and gunwale ending and simply pulling it up in one long string. It will probably break in the process along the string - just keep repeating. Sand off the remainder but this will leave a problem as the 2 edges which are adjacent to the cabin sides and gunwale - hence might well need the polyurethane 2 pack renewed on these. Depends what your budget, time and desired result is.

For the blue paint would suggest it all needs to be removed - can't think of anything else but using a suitable paint stripper to get all of it off - this would probably need multiple applications and be very messy - do it in small areas at a time and it will probably need multiple applications. And maybe after that acetone or isopropyl alcohol and stiff plastic bristle scrubbing brush will probably be needed. Then sand and apply the Kiwigrip iaw their instructions. We have used Kiwigrip recently and it is brilliant. For your case it wouldn't hurt to contact them directly to check if the above is logical - if not what would they recommend. Whatever I can't see anything being painted over the paint and sealant you show there - surely it all has to be removed completely.

www.pyiinc.com/KiwiGrip/

Ramona
NSW, 5889 posts
25 Sep 2020 5:40PM
Thumbs Up

It looks like some sort of swimming pool rubberized stuff. I would suggest chiselling up a bit and having a look. I agree that it will have to come off.

jbarnes85
NSW, 157 posts
25 Sep 2020 5:41PM
Thumbs Up

I recently did a boat with kiwigrip. They are super helpful if you contact them. my boat was gelcoat in poor condition with some raw glass showing through. Lots of cracks.
if it was me I would attack it with a wire brush and scraper. If the blue paint is holding then the kiwi grip will probably hold to that. Then maybe a coat of primer and then the kiwigrip.
the kiwigrip covers every imperfection really well. Put it on thick. The spikes wear down with time. Practise on some ply. Then practise on the anchor locker hatch or something. I used a notched trowel to spread evenly before using the roller.
I would however be running the plan past the guys at kiwigrip.

jbarnes85
NSW, 157 posts
25 Sep 2020 5:43PM
Thumbs Up

Select to expand quote
jbarnes85 said..
I recently did a boat with kiwigrip. They are super helpful if you contact them. my boat was gelcoat in poor condition with some raw glass showing through. Lots of cracks.
if it was me I would attack it with a wire brush and scraper. If the blue paint is holding then the kiwi grip will probably hold to that. Then maybe a coat of primer and then the kiwigrip.
the kiwigrip covers every imperfection really well. Put it on thick. The spikes wear down with time. Practise on some ply. Then practise on the anchor locker hatch or something. I used a notched trowel to spread evenly before using the roller.
I would however be running the plan past the guys at kiwigrip.

If it's rubbery maybe ignore what I said. Maybe it won't stick. Perhaps try overcoating a section to see how it goes.

Karsten
NSW, 317 posts
25 Sep 2020 5:47PM
Thumbs Up

What a great reply with complete attention to detail by R13.

Just out of interest - if you use the paint stripper and brushing/sanding as described, what does the original moulded non-skid pattern look like at the end - is the intention to end up with totally flat surface, or will the pattern still have ridges and valleys?

If there's still ridges, the valleys will be filled with left-over blue paint. How do you get rid of that - simple as a bit more paint stripper or would you need mechanical removal?

Microbe
WA, 91 posts
25 Sep 2020 3:51PM
Thumbs Up

Thanks r13,

the boat is a Spacesailer 22 that I've had for four years and has always been a fixer-upper. I've been too busy sailing her and other stuff to worry too much about the deck before now. Here's a shot from when I first bought her. I replaced the windows because they were crazed and leaking, and whilst I had them out I painted the cabin sides with single pack polyurethane.

Luckily she's a small boat, so there's not too much crappy blue to strip off, and that section around the chainplates is the worst section.


r13
NSW, 625 posts
25 Sep 2020 6:47PM
Thumbs Up

Thanks Karsten, great comments as always from Ramona and jbarnes85.

As regards the original moulded non-skid pattern I would expect that - depending on what the paint is - it should essentially all come off with the suitable paint stripper probably applied more than once, then the acetone or IPA, including in the valleys of the original moulding pattern. Certainly the intention is not to flatten out / smooth out the original moulding peaks to get a smooth flat surface - no need to do that just get rid of all the blue paint. For sure if the valleys cannot be cleared of the blue paint with multiple paint stripper applications and acetone or IPA - note that removing the paint everywhere including in the valleys is the reason for the recommended use of these 3 chemical solvents - sure some mechanical rotary wire brush means should be used. But this is where the Kiwigrip gurus come in - as per above get their input so that you don't have to waste too much time or effort on the valleys if they become a major task to clear. They will recommend a suitable primer presumably once most of the blue has been removed. But there is nothing worse than putting a new coating system over an inappropriately prepared surface and expecting it to come up as new - including an inappropriate paint system left there.

Microbe the S22s are obviously a brilliant boat - wish more were over here in Sydney so I could buy one. I would take the anchor locker or forehatch home and do the process in your shed, including optimising it, then move on to the rest. The effort will be well worthwhile for that boat. A 2 pack undercoat before the Kiwigrip would be recommended - check with Kiwigrip - this one should be suitable;

www.boatingcentral.com.au/products/norglass-shipshape-epoxy-primer-undercoat?variant=31970599534675&sfdr_ptcid=39153_389_638879944&sfdr_hash=52825ce878ac8a96d131c145478c8aaf&cmp_id=10269106712&adg_id=102482714797&kwd=&device=c&gclid=EAIaIQobChMI2oLQtPWD7AIVxHwrCh0L7wp1EAYYASABEgJMcfD_BwE

rumblefish
TAS, 822 posts
26 Sep 2020 10:34AM
Thumbs Up

Replace the rigging and check to chainplates while you're at it!!
Those turnbuckles look around 20+ years old and I don't like the look of the chainplate welds!
Fancy deck is no good if the mast falls on it!!

oldboyracer
NSW, 273 posts
27 Sep 2020 8:37AM
Thumbs Up

Well I think you have done the best thing " to busy sailing her " which is what sailing boats are for. Now I second replacing/ checking rig and chain plates before making it look pretty. Can't advise on the paint except kiwi grip seems to stick and cover everything as long as the surface your painting is not peeling off. Don't forget to post pics of progress .

Harb
WA, 216 posts
27 Sep 2020 10:48AM
Thumbs Up

Select to expand quote
Microbe said..
Hi, yet another deck repair and painting thread.

I'm planning to refresh my tired old deck with kiwi-grip.

Current deck condition is chalky paint over molded non-skid. There's plenty of cracks in the surface. What do I need to do to prep before applying Kiwi-grip. Should I dremel out the cracks and fill? Or would scraping and sanding be sufficient?

TIA


How much time and effort do you want to put into it ?
A proper job would involve sanding the whole lot down to glass and restoring the surface.

If you want to a quick cheat you could painting some slow cure epoxy and using an electric heat gun warm up the surface and epoxy as you paint it on. This lowers its viscosity which will help it go trough the cracks all the way down , as the air in the cracks expands and contracts it also helps to suck in the epoxy. You can heat up the epoxy close to boiling point and you'll go through a few epoxy brushes to do the entire boat but will save days of dremel work.
I'd practice on a small patch first to get the hang of it.

Microbe
WA, 91 posts
28 Sep 2020 2:06PM
Thumbs Up

Select to expand quote
rumblefish said..
Replace the rigging and check to chainplates while you're at it!!
Those turnbuckles look around 20+ years old and I don't like the look of the chainplate welds!
Fancy deck is no good if the mast falls on it!!


Good point rumblefish. Rerigging is also on my to do list. Its going to be a while before I can get space on the hard stand to do any painting, so I'll focus on the rigging and paint prep first.

Can those chainplate fittings be bought off the shelf, or are they always custom made?

Microbe
WA, 91 posts
3 Oct 2020 6:18PM
Thumbs Up

So I did a bit of investigation and pulled up a bit of paint near those cracks. Looks like the cracks go all the way through the gel coat. I can see some of the glass fibre showing through. The chips came up really easily and there is signs of dirt underneath the gel coat - getting in through the cracks i guess. The cracking is only in a few spots near the chainplates. Any tips on how to proceed?


woko
NSW, 789 posts
3 Oct 2020 8:30PM
Thumbs Up

The paint and gel coat cracking could be a sign of weakness of the chain plate attachment, or over tension at some point, I'd be investigating possible deck flex 1st, then grind out all the offending material and lay it up with epoxy

r13
NSW, 625 posts
3 Oct 2020 8:59PM
Thumbs Up

Yes for sure agree with Woko who is always spot on.

That photo is not good obviously.........it is very zoomed in please can you post a few more photos progressively zooming out so the extent of that damage can be seen around the chain plates.

Many small yachts have deck lift around the chain plates potentially due to unacceptable strength initial design of the chain plates and ply bulkhead they are bolted to, or water ingress from the deck down under the chain plates so as to rot and weaken the ply, or corroded chain plate bolts, or a combination of all 3, or other.

The S22 have a good class association here and would suggest you contact them - one of their members will surely be able to diagnose the root cause source or sources of your deck issues and advise a solution. See also facebook page;

www.spacesailer22.org.au/association/index.html

www.facebook.com/Space-Sailer-22-318676201822023/

They should also be able to answer your question regarding if the the chain plates can be bought off the shelf, or if they have to be custom made. I would doubt if you could buy them off the shelf now but hopefully the class assoc has design drawings where you can have a suitable stainless fabricator - probably in the Henderson area - make them up.

The chain plate design does not look too flash sorry to say - very unusual to have the cap shrouds and diagonals having separate welded fittings in a 22footer. Maybe they go down into stainless flat bar straps each side of the main bulkhead, securely bolted with a suitable array of bolts in shear. The ideal is to have a single suitably thick and wide and long stainless flat bar for both shrouds per side, securely bolted to the main bulkhead - no welds. Inboard hole for the diagonal, outboard hole for the cap. Possibly the class association can advise if such a design improvement has been instigated. It would be very easily implemented.

Microbe
WA, 91 posts
3 Oct 2020 7:43PM
Thumbs Up

Yep. I'll definitely be fixing up the rigging before I go sailing again. Bit of work to do. The chainplates are fastened through the deck to plates that spread the load and there is a strap on the inside of the cabin, from the cabin side to half way down the hull. The rig is held up by four bolts each side.

Here's a wider shot of the deck showing general position of the patch i scraped back.





garymalmgren
630 posts
3 Oct 2020 7:44PM
Thumbs Up

The chain plate design does not look too flash sorry to say

Not to flash is a bit of an understatement. there r13.

My guess is that it is Perth based and that chainplate configuration is for lowering the mast.

Up-down, up-down, wobble, wobble and you end up with damage around the chainplate bases.
As Woko and r13 have suggested (and the photo confirms, you have de-lamination, gel coat failure and probably water ingress into the area shown and probably other spots hidden under the blue goo.
You are probably lucky that the blue paint (whatever it is) comes way reasonably easily.

It is decision time.
1/ What is the condition of the rest of the boat?
2/ Are you prepared to spend between $5oo and $1000 on materials. (epoxy, glass, kiwigrip etc)
3/ Are you prepared to spend the time to remove the blue goo, grind back all of the suspect areas, replace suspect chainplates (I personally am not sure that is necessary), place pads underneath and re-glass, grind back and cote with undercoat and kiwigrip.
4/ Do you truly LOVE the boat.
5/ is it on a mooring or in a pen? On a mooring you will need a generator to tackle the job. Also on a mooring it will take 30% longer than you anticipate.


So, more photos please as r13 has requested.
that will help us help you come to a decision.

gary

garymalmgren
630 posts
3 Oct 2020 7:46PM
Thumbs Up

That scraped patch is further from the chainplates than I thought.
The "A" frame for lowering the mast can be seen in the photo.

gary


Ramona
NSW, 5889 posts
4 Oct 2020 8:58AM
Thumbs Up

If it was my boat I would grind out the section of the deck with a battery powered grinder with a 36 grit flapper wheel. Lay up with fibreglass cloth and epoxy. Smooth off with the grinder and slop on some special purpose grey primer and go sailing.
Spend a few days sailing about the river and have a think about what you need to do next.

I would motor off somewhere and anchor as far away from pensioners as possible to do the grinding. If you have to buy a Ryobi grinder and a flapper wheel and the epoxy you will be looking at about $200.

Achernar
QLD, 165 posts
4 Oct 2020 1:50PM
Thumbs Up

Select to expand quote
Microbe said..
Yep. I'll definitely be fixing up the rigging before I go sailing again. Bit of work to do. The chainplates are fastened through the deck to plates that spread the load and there is a strap on the inside of the cabin, from the cabin side to half way down the hull. The rig is held up by four bolts each side.

Here's a wider shot of the deck showing general position of the patch i scraped back.






Is it a trailersailer?

You've got an A frame and an extended chain plate for raising or lowering the mast. However, that could be there to get under the Fremantle Bridge.

If a trailer sailer, get a trailer and drag it somewhere to work on it. (PS getting a trailer for a trailer sailer is a mission, and you could easily spend more on the trailer than the value of the boat)

Microbe
WA, 91 posts
4 Oct 2020 12:33PM
Thumbs Up

Keen eyes have noticed my temporary A frame set up for dropping the mast to transit the Freo bridges (its been temporary for several years and two boats now).

The boat lives on a mooring on the river in Freshwater Bay. The local yacht club have haul out facilities available and would actually be the cheapest option for a couple of weeks on the hardstand. Unfortunately it's a busy time of year for all the yards, so they can't fit me in till March.

Cordless tools it is! And some sort of tent to catch the dust and crap.

Harb
WA, 216 posts
4 Oct 2020 8:19PM
Thumbs Up

Select to expand quote
Microbe said..
So I did a bit of investigation and pulled up a bit of paint near those cracks. Looks like the cracks go all the way through the gel coat. I can see some of the glass fibre showing through. The chips came up really easily and there is signs of dirt underneath the gel coat - getting in through the cracks i guess. The cracking is only in a few spots near the chainplates. Any tips on how to proceed?



Ouch! The gel coat is the least of your worry. The dry fibers in the glass is bad news and like Ramona said you'll have to strip it all back to glass then use epoxy to wet it then cover it with a layer of multiaxial fiberglass cloth. BIG job and you'll be needing a bit of epoxy and cloth to do the whole job. Maybe worth looking at getting the materials before you start stripping back the gelcoat. I get my epoxy and cloth from trojanfibreglass.com.au/product/500-series-epoxy-laminating-resin-51/ and takes about 1 week to arrive from Newcastle but a bit cheaper then Fibreglass and Resin Sales in Welshpool.

If you have access to 240V forget the battery grinder and get yourself a 7" variable speed car polisher with M14 spindle thread so you can use 5"-7" velcro pads and sanding discs. The speed controller allows you go down to a few hundred rpm which gives you better control of how much material you remove with it and leaves you with flatter surfaces then a flap wheel. For fast strip use 40grit and when it comes to sanding down the filler you can use 80-120 grit then 240 grit to sand the primer.
Don't know where you can get 7" velcro pads and sanding discs locally since I've got mine from eBay but the 5" pads and discs you can get from Bunnings. I kept the old velcro pads with worn edges and old sanding discs and cut them down to smaller sizes all the way to about 2" so I can get them into tighter spots and corners where the 5" won't fit.
This is the 7" car polisher I got from eBay to use for sanding and shaping fiberglass and wood and for cutting glass I use the 5" grinder with 1mm or 1.6mm metal cut off discs.




DrogueOne
VIC, 86 posts
5 Oct 2020 1:06PM
Thumbs Up

I'm itchy from the dust already. Looking at your original picture it looks like there was some sailtrack along the deck there. you can see the round holes. These may not have have been filled which would provide ingress of moisture into your laminate that may have advanced it's degradation.

Lots of good advice about how to remedy it, I would be thinking about the effect on safety and hull/deck/rig integrity and how far you go in digging it out.

Of more concern to me is the cracks and discolouration in the chainplate area in the first photo. Irrespective of repairing the remainder of the deck surface I would be looking at those bolts as they are a candidate for crevice corrosion. What do they attach to on the inside? Even if the nuts look OK, you may have some weakening of the bolt shank.

woko
NSW, 789 posts
5 Oct 2020 8:32PM
Thumbs Up

I've become a veteran of useing a grinder on a moored boat, and yes the battery jobs are OK for little patches, a 240v 5" can be run from a small generator and beats the battery job hands down. A tarp strung along the life lines and a blower vac to vac with keeps the job mostly contained. I try to chip as much out as possible to reduce the fine mess, it's easy with steel, just hit it with a hammer ! And by the way that smiths and arrow gear that Ramona pointed to is all top quality, cheaper than the big green shed and delivered pronto

Ramona
NSW, 5889 posts
6 Oct 2020 8:56AM
Thumbs Up

Select to expand quote
woko said..
I've become a veteran of useing a grinder on a moored boat, and yes the battery jobs are OK for little patches, a 240v 5" can be run from a small generator and beats the battery job hands down. A tarp strung along the life lines and a blower vac to vac with keeps the job mostly contained. I try to chip as much out as possible to reduce the fine mess, it's easy with steel, just hit it with a hammer ! And by the way that smiths and arrow gear that Ramona pointed to is all top quality, cheaper than the big green shed and delivered pronto


When you buy it on special. The Zirconia seems better than Bunnings stuff. Brilliant on stainless steel and makes short work on fiberglass.

woko
NSW, 789 posts
6 Oct 2020 10:00PM
Thumbs Up

Select to expand quote
Ramona said..

woko said..
I've become a veteran of useing a grinder on a moored boat, and yes the battery jobs are OK for little patches, a 240v 5" can be run from a small generator and beats the battery job hands down. A tarp strung along the life lines and a blower vac to vac with keeps the job mostly contained. I try to chip as much out as possible to reduce the fine mess, it's easy with steel, just hit it with a hammer ! And by the way that smiths and arrow gear that Ramona pointed to is all top quality, cheaper than the big green shed and delivered pronto



When you buy it on special. The Zirconia seems better than Bunnings stuff. Brilliant on stainless steel and makes short work on fiberglass.


Give the poly stripper discs a go, seem to be able to remove all manner of coatings without gougeing metal substrate ie. Car panels / propellers etc,

Jolene
1303 posts
6 Oct 2020 7:59PM
Thumbs Up

Yep, the Poly stripper disk's aka brumby disk)
are the shot

Microbe
WA, 91 posts
7 Oct 2020 10:00AM
Thumbs Up

I've done a bit more research with the SS22 association.

The plans say the deck layup is:
1 x 300 g csm
2 x 450 g csm
coremat or foam in horizontal areas
plywood in way of major deck fittings
2 x 450 g csm

I assume that's from top to bottom.

Another SS22 owner has done a similar repair in the chainplate area. He cut out the top layer of glass, dug out the core and replaced with thick ply and reglassed over the top. He was working with a smaller area of deck - my cracked area is about a metre long, but I think I will do my repair in the same way.

For chainplates he is using heavy saddles bolted through the deck with a stainless backing plate on the inside. There is no internal bulkhead in the SS22 for the chainplates to attach to. Instead a stainless strap or wire strop takes the load from the chainplates to the hull. He uses an additional saddle on the underside of the deck, on the same bolts as the deck mounted saddle, which then attaches to the strap to the hull. He's been using this system for years and sailing the boat hard in club races, so it seems reasonably strong - despite the bolts not being in shear. Its a bit better than my current arrangement as it removes the dodgy welded chainplates from the system.

Its going to be a busy couple of weekends!

r13
NSW, 625 posts
7 Oct 2020 5:52PM
Thumbs Up

Well done on your research there including getting feedback from another owner. Class sites usually have very good information and a wealth of background details on design improvements if needed.
I am very surprised that at least the cap shrouds don't go down to a stainless strap shear bolted to a suitable bulkhead - see below photos of Columbia 22 arrangement where the caps go to such a bulkhead and the fore and aft lowers go to stainless plates under the side deck adjacent to the cabin side junction corner. So this provides a nominally suitable arrangement but these days fore and aft lowers are not used on such small yachts and the single lower diagonal goes to the same spot as the cap, with swept back spreaders also being used to avoid the inner forestay.
Anyway it nominally sounds like a good re-design arrangement - but ideally the ply core you are inserting and the new epoxy resin glass work would go from that badly damaged area to say 300mm aft of the aft lowers. So this means mast down to do the repairs.
The next issue is what is the hull topsides structural arrangement at the junction of the ss straps or wire strops from the cap and diagonal saddles under the deck? If this is not solid enough the topsides will pull in like a hungry horse. Am sure the owner who has done this has it sorted suitably and he has advised you the details - would trust it is a large ply gusset going the whole width of the sidedeck down to the saloon settee berth junction with the inside of the hull - hence making a partial gusset bulkhead very well glassed into the side deck, topsides and settee berth junction.
See 3rd attached photo below I just found this on the web where the SS22 arrangement seems to have a ss strap shear bolted to the cabin side then going to a fitting at the settee berth to hull side junction, and a wire strop also. If properly done this should work but the details of the fitting on the hull side is hard to see - looks like 2 bolts in shear holding the strap and strop, presumably suitably csunk bolted through the hull down lower under the junction. The above deck chain plate could be a 3 bend bent flatbar with the 3 bolt leg on the cabin side holding the cap, and the 2 bolt leg along the deck laterally holding the diagonal by means of large saddles above and below. I don't want to interfere but if you want me to do a mud map sketch of this 3 bend flatbar this is easily done please advise.










Microbe
WA, 91 posts
7 Oct 2020 3:18PM
Thumbs Up

Thanks for your detailed response r13.

I'm planning to pull the mast down and replace all the standing rigging and turnbuckles. I've been taking a bit of a risk sailing with it as is without knowing the age and actual condition of what's there. Time to set things right.

Here's some pics of the interior of my boat showing the strap that is supposed to take the loads to the hull. However, there is no tension on that strap, and it does not connect directly to the chainplate attachments, going instead to the nearby cabin side. I figure this would allow for a bit of deck flexing under sailing load and may have been the cause of my deck issues.

Interestingly the chap from the SS22 assn said that the lowers have more force on them when sailing than the cap shrouds - which is opposite of what I've always thought.

The lower end of the strap attaches to a single bolt protruding from the glass. Not sure what is behind that, and the bolt does not go all the way through the hull, so would be a pain to replace. I'm considering glassing in a triangle of ply to fill in that triangle formed by side deck, hull and strap. Then I could add some extra bolts along the length of that strap.

I'd be interested in a mud map of the three bend flat bar you mentioned - not sure I quite understand what you mean.







Subscribe
Reply

Forums > Sailing General


"Deck repair advice" started by Microbe