Skerry epoxy concerns

Hi everyone.  I have no experience in lapstitch construction.  I'm looking at a used Skerry which is for sale. Construction in general looks alright but where the thwarts and seats join the hull, the epoxy color doesn't match the hull color.  It's quite white and looks a bit carelessly applied.  This is also true of the joint between the two pieces of the mast.  The color around the joint is yellow-white as opposed to the deep, rich hull color.  All these joints feel strong but look a bit amateurish.  Should I consider this a potential problem in epoxy mixing or application?  Could it compromise hull strength?  Sorry, I have no photos to show you.  Thanks for your input.  Cheers. Steven

 


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RE: Skerry epoxy concerns

   hmmm, probably gonna need more details.  The way you mention it, sounds like only part of the epoxy work doesn't match?  Could be repairs...  Kit or plan built?  Could just be the wrong color.  Not neat isn't a seaworthy no go criteria, but gives cause for closer inspection.

Is your impression is has always been that color, or turned that color at some point.  A change would definitely be cause for alarm.

I'm not experienced here, but curious to know if it's at all feasible to basically grind out fillets and replace them?  Tedious for sure, but doing at least some of it could give a good indicator as to seaworthiness.

Good luck!

Mike

RE: Skerry epoxy concerns

Thanks Mike.  I I don't think I can upload photos on this forum (can't seem to locate that function, at any rate), but I may be able to email you a few closeup photos sometime in the next week when I go back to see the boat again, if you're willing.  

I get the impression those areas of different epoxy color were always like that.  They only occur along the edges of the thwart-to-hull, seat-to-hull and mid-mast joint.  Perhaps he just added some extra epoxy later for extra strength and didn't get the color right.  Unfortunately I'm unable to contact the builder to ask him.  

If it's mere cosmetics, that doesn't bother me.  My concern, as a newbie to wooden boats, is with structural integrity.  When I return to see the boat again next week, I will take a friend who knows more about these things than I do, and if necessary, I'll get a few good photos.  I'll give you my email address, and if you're willing to give me your email address, I'll send you photos when I get them, if I have any remaining doubts at all. 

Thanks and Cheers,

Steve

stevie44@me.com 

 

RE: Skerry epoxy concerns

color, other than some exceptions i will get to shortly, is not really an issue with fillets other than cosmetic.  fillets rarely match the color of the underlying wood unless the builder is incredibly careful and advanced in their work.

whitish fillets are probably simply becuase the fillet was primarily composed of cabosil.  dark brown ones would be primarily wood flour.   and some folks spend a lot of time to try to sort out a blend thse two components to get something that is close to a match to Okoume.   variation in color is probably just an indication of learning during the build process.

now the exceptions would be if the fillet is white becuase it is cracked and has seperated from the underlying thwart/seat/hull,  when epoxy cracks, white is the typical look...you would probably also detect something jagged that looks like a crack....  another exception is if the fillet is not hard and fully cured.   

so as long as the fillet is actually hardened and not cracked, it is not a problem with the epoxy....color is almost always about the additives that were used to create the fillet and their color.   so i would not worry about strength.

on fixing the problem, grinding out fillets is a lot of work and i would probably not go there.   that said, sometimes you can go over a fillet with a new mixture of your desired color.   this works if the fillet you are going over is undersized relative to what you want.  if i had to remove a fillet, i would use heat from a high quality heatgun to soften the fillet and then you can cut it out with a butter knife while the section of heated fillet is still warm/soft.   its actually pretty easy once you get the hang of it.  its only down side is the risk of burning the boat (creating a blackspot) if you dont control the heat properly...so always train on a scrap piece of wood until you get comfortable with your heatgun.   painting a fillet is an option as well..  but all of these are probably more hastle than its worth.....buy the boat, finish it and go have some fun.   you can apply these 'fix it' options anytime in the future....so maybe its best to wait and see how you feel about it after a season or two.

the other thing i would suggest is to check out the 'builders club' on the site  https://www.clcboats.com/builders_club/search/   and contact a builder who is close by to come take a look with you.  if you have not done this kind of boat building before, i would take an experienced builder with you to help you assess the situation.  its also a great way to meet folks and a task i am sure somebody would gladly help you with.

all the best

h

 

 

 

RE: Skerry epoxy concerns

   I'm about 99% sure the fillets are simply epoxy mixed with filler.  Epoxy is generally clear and will take on the color of the filler.  In model airplanes we use micro balloons, have used talcum powder, heard of wood flour being used... It's not altogether different than aggregate in cement.

However, there are pre mixed fillers in some fillet stuff.  Sig model airplane co made epoxylite.  Brodak co makes something similar, but has a 2:1 mixing ratio.  On real airplanes there's yet another one.  They are labeled as epoxy based, don't know how they compare in strength to what I call regular epoxy and filler.  Seem strong though.

I would be concerned if we thought it was bondo or something.... Polyester resin?

Shoot me pics, maybe I can post them and I'll certainly tell you what I think, please keep in mind I am no expert here.  Signing up for the dory class in October!

Mike.  n0kkj@yahoo.com.  Ham radio call sign, it's a zero, not the letter oh.

RE: Skerry epoxy concerns

 

   Thanks h.  I've just examined a bunch of photos online of Skerrys and have discovered what you've pointed out, that fillets vary in color from quite white to dark brown.  You've explained the reasons why very clearly.  I am new to stitch and glue construction and want to be fully informed about the boat I'm considering.  I think the builder could've applied the fillets in a more aesthetically-pleasing manner, but it seems they are sound.  I can't locate any areas where the thwarts and seats seem to be separating from the hull, and so I think I'm going to be fine.  I'll have another look of course, and am taking a friend along who knows about stitch and glue construction, but I'm encouraged that this is merely a cosmetic issue.  You've been most helpful.

The Skerry is a gorgeous design and I'm looking forward to having my own.

Cheers,  S.

 

 

RE: Skerry epoxy concerns

If the structure is sound...well...there's always paint.  A shapely boat like a Skerry looks pretty good with a decent paint job letting the shape speak for itself.  Not that a decent paint job is easy to acheive, either, but it's a whole lot less trouble to get and keep than brightwork.  Of course, if you've got the chops for it and enjoy the varnishing for its own sake, and if the joinerwork beneath is worth showing off, by all means go for it.

For the rest of us who are more boatwrongs than boatwrights...hey, it's a boat, not a Martin guitar.  You're going to be scraping it against concrete piers and maybe have people tromping around in it wearing combat boots.   I've said it before, and I'll likely say it again: It is my belief that varnish is a tool of the devil, straight from the workshops of hell, meant to enslave mankind to his own vanity.  Paint, on the other hand, is God's gracious gift to poor, fallible boatwrights, the better to cover their imperfections.  <;-)

So, if the boat is sound but the appearance is unactrive due to sloppy, discolored, or oddly colored epoxy work, paint might be your best friend.

.....Michael

RE: Skerry epoxy concerns

   Thanks Michael.  If I decide at some point to paint part of the cockpit, what preparation needs to be done first?  Thanks.

RE: Skerry epoxy concerns

Here's a picture of the first stitch&glue boat I made. The seams ended up huge and rough, so I decided to paint it (paint covers a multitude of sins). It took a month of before & after work prep to get it ready for painting, mostly waiting for things to cure or dry.

First, I took care of all the rough fillets (and other areas) by applying epoxy/phenolic microballoon mix. This is a non-structural fairing compound that's easy to sand. Then I wrapped sandpaper around  used rollers and used that as my sanding tool for the fillets. It was much easier than sanding the epoxy. After that is was just masking and priming, sanding the primer, re-applying primer and sanding some more until finally painting.

As you can see above, the fillets came out nice and smooth. Be aware that for a finish this slick you're going to need Seadek or some other anti-skid system to keep from falling on your donkey when you step into the boat

Have fun,

Laszlo

RE: Skerry epoxy concerns

After my paean in praise of blessed paint, suilven poses a good question to which I do not have a ready answer: how does the humble boatwright safely and efficiently remove old varnish from epoxy plywood surfaces so that they may be painted?  Stripper?  Would that remove or damage epoxy as well?  Is there a safe-for-epoxy stripper that way?  Does that depend on the sort of varnish?

Otherwise, what?  Heat and scrapers?  Maybe just sand the varnish down enough to give it some "tooth" (being careful not to get into the epoxified plywood beneath) and paint over that?

All my own experience with removing paint and varnish doesn't include epoxified plywood like this.  I hadn't thought about the boat in question being already varnished.  One of these years, the paint and small areas of varnish on our PMD will be beyond mere touching up, so I'd be interested in learning how to remove the old completely without making a hash of it.  Enquiring minds want to know.  <;-)

.....Michael

RE: Skerry epoxy concerns

   I would think you could sand and paint right over the varnish, I can't see a reason to remove it completely.  As you mention, just be careful not to compromise the epoxy.

On wooden aircraft structures being covered with an MEK based product, they are varnished AND THEN epoxied, to protect the varnish from the MEK, which epoxy is nearly impervious to.

Point is, if you were worried about the epoxy substrate, you could sand, for appearance and tooth (not specifically for removal) then recoat epoxy, and then paint.

Mike

RE: Skerry epoxy concerns

Oops, I missed that the question was about painting an already-varnished surface. Unless the varnish and paint manufacturers are one and the same and specifically tell me that the varnish and paint are compatible (which so far has happened exactly never), I remove the varnish.

With Schooner varnish I've found that wet sanding will remove it and leave the epoxy ready for priming and painting. Not only does wet sanding keep the dust under control and avoid the issues caused by heat and harsh chemicals, it also lets you know when to stop sanding. Wet sanding Schooner has a soapy feel that goes away as soon as you get to the epoxy. I don't know if this is also the case for other varnishes since I've only used Schooner over epoxy.

Good luck,

Laszlo 

RE: Skerry epoxy concerns

Laszlo,

Thanks for the helpful technical info.  You have that cockpit gleaming!  Nicely done.

Cheers, Steve

 

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