For below waterline applications you need products designed for full emersion. Many are not, like house paint and topside marine paints! Sealing your repair with epoxy is the best next step. This can be done using fiberglass and then fairing the keel to original shape. The bottom will need to be covered to protect the fiberglass and epoxy repair from UV (when boat out of the water). Bottom painting is one option. Choose a bottom paint that has good reports for antifoul success for your area. Each area finds different antifoul paints work better than others. Follow the chosen paint's steps for application over epoxy to the letter. If you don't follow the steps the paint will not stick! The other option is to gel coat - but you need to wait as the epoxy must be fully cured! This differs by product but most say at least a week. I'd at least double or triple the cure time. Once FULLY cured remove blush and then prep. Polyester gel coat doesn't like to stick to epoxy but with full cure and correct prep (ie, full sanding with absolutely no slippery spots left and removal of blush) it can be done. The negative is now you need to sand the gel coat smooth so it has no 'orange peel' (ie little bumpy from spraying or rolling) - this is not at all fun. So I recommend you antifoul the bottom as it will be faster and less work. You applied a aluminum product over steel. This will cause galvanic corrosion. Your best bet at is to seal the area as best as you can so it doesn't get wet. This will slow/limit the rusting. For this reason cover with an epoxy and then use a barrier coat (ex, Pettit Protect or Interlux 2000e) and then antifoul. If you use a Pettit paint use Protect and Interlux use 2000e. As I wrote above follow the instructions as they will define how to prep and how to overcoat. :: Dave Scobie :: M6'8" #650 :: SV SWALLOW - sv-swallow.com :: former owner M17 #375 SWEET PEA - m17-375.com :: former owner M15 #288 SCRED - www.freewebs.com/m15-named-scred/ On Fri, Jun 7, 2019, 4:59 AM edwin jenkins <ejenkins1953@gmail.com> wrote:
Thanks
On Thu, Jun 6, 2019, 10:04 PM John Schinnerer <john@eco-living.net> wrote:
Yeah, see what others have to say about after the epoxy repair. I'm not so familiar with barrier coats and bottom paint and all that, have been learning a bit on this list.
You don't want to use fiberglass mat though, you want to use woven fiberglass cloth. Six ounce cloth should be fine, it's mostly to make the repaired area a uniform surface overlapping the undamaged area around it.
FWIW I have been using Raka brand epoxy for various boat stuff for some years now, seems good quality and a fair bit less pricey than the "big names" like System 3 and MAS and West Systems. Raka also sells cloth, fillers, other supplies. http://raka.com/
Duckworks sells Raka epoxy now also (as well as some System 3 products), and cloth, fillers, etc. https://www.duckworks.com/
cheers, John
On 6/6/19 6:36 PM, edwin jenkins wrote:
Thanks for the tip, the damage is about half way up towards the front. I'm all for over kill! Sounds like a good plan to me. I know the material I used is pretty tough stuff but not water proof. I like the idea of over lay with fiberglass mat with epoxy. Then paint over it with epoxy paint then antifouling paint. Would that be good?
On Thu, Jun 6, 2019, 5:24 PM John Schinnerer <john@eco-living.net> wrote:
I'm not clear where the crack or split is - on the side somewhere, the bottom edge, front or rear edge?
Is your layer of bondo already flush with the surrounding keel? Or is there still some depth to fill?
If the latter, I'd fill the last bit with epoxy resin thickened with silica powder.
Then after underlying repairs and filling crack to flush with keel, I'd put a layer of light (e.g. 6 oz.) fiberglass cloth and epoxy resin over the whole area of crack/split repair, with at least 3" overlap onto undamaged keel material, which should be sanded down to underlying fiberglass/resin layup for good bonding of new material. This gives you the waterproofness of epoxy, with cloth for structural integrity of the epoxy, well overlapping whatever is underneath.
Saturate the cloth, then fill the weave, then sand smooth the whole area (without cutting into cloth weave! Just removing excess weave fill epoxy). Then feather the edges of the glass down to the surrounding keel surface.
Then after full epoxy cure time, whatever prep, primer and finish layers suit your situation - barrier coat and antifouling if you need it, or just some kind of appropriate finish paint. That stuff I know a lot less about.
I am generally of the "do it well, do it once" repair mindset so the above may seem like overkill, depending on the size and type of damage on your keel. For me it beats the alternative ("do it poorly, do it again").
There was some damage to my keel from a prior owner where the stop pin had been busted out on one side at some point. The 'repair' was a joke, they put a lot of caulk in there and maybe some hardware store epoxy and maybe some bondo too. Better they had never fixed it than to 'fix' it so badly. I spent at least as much maybe more time digging through and clearing out the crap repair job as I did rebuilding the area.
cheers, John
On 6/6/19 1:30 PM, edwin jenkins wrote:
This product is a fiberglass long strand is stronger than regular bondo, How ever it is not waterproof . so my question is do I gel coat it or use an epoxy paint to seal it .” total protect” has an epoxy primer 2 part system that claims it seal small cracks in the gel coat and seals out water. I have read posts on this and seems to be a lot of opinions on this so I am a little confused. Thanks for any in site on this Ed
Sent from Mail for Windows 10
From: Dave Scobie Sent: Wednesday, June 5, 2019 9:10 PM To: For and about Montgomery Sailboats Subject: Re: M_Boats: #100 1975 Montgomery 17
Edwin.
The ballast of your boat is steel. Actually the centers left over from making washers.
First, before talking about what to do to finish the repair - What type of body filler? In general automotive filler isn't appropriate for boat use as it has to much talc and will absorb water.
:: Dave Scobie :: M6'8" #650 :: SV SWALLOW - sv-swallow.com :: former owner M17 #375 SWEET PEA - m17-375.com :: former owner M15 #288 SCRED - www.freewebs.com/m15-named-scred/
On Wed, Jun 5, 2019, 5:51 PM edwin jenkins <ejenkins1953@gmail.com> wrote:
Ok gentlemen , I purchased a 1975 Montgomery 17at an auction with trailer and a 3.9 Volvo outboard for $100.00 a couple of years ago and I am restoring it now it hasn't been in water for approximately 15 years first thing I did was took it to a carwash and spent$20.00 to clean it up. Came out looking pretty good. I'm in the process of redoing the keel . It had a nasty split in it so I cut out a section and put a coat of liquid aluminum on the led pellets after grinding that smooth I put a coat of body filler with fiberglass strands in it . Now I'm debating whether I should also put a layer of fiberglass matting on it or should I just put a coat of epoxy on it ? .
-- John Schinnerer - M.A., Whole Systems Design -------------------------------------------- - Eco-Living - Whole Systems Design Services People - Place - Learning - Integration john@eco-living.net - 510.982.1334 http://eco-living.net http://sociocracyconsulting.com
-- John Schinnerer - M.A., Whole Systems Design -------------------------------------------- - Eco-Living - Whole Systems Design Services People - Place - Learning - Integration john@eco-living.net - 510.982.1334 http://eco-living.net http://sociocracyconsulting.com