Big trouble.....
February 04, 2020 02:35PM
So ran into a snag. Glassed/resined the interior x 1 layer of the plascore bottom. Have "fast" hardener, RAKA. 10 oz glass cloth. Was Unseasonably warm the day we put it down. Cooled off that night, but shop is metal and unheated/aired so tends to retain ambient temp for a while. Did apply in the late afternoon so an overall cooling trend should have been in place. No issues while applying it. High temp around 70. 2 days later, bubbles galore all over the bottom. Pic looks better than the real thing, tons of smaller bubbles that didn't show. I'm certain the temp, hardener, and inexperience caused the goof.....I've just got to sort out what to do next. Can't exactly ditch my boat bottom. Cut out bubbles and resin in? Cut out and lay in cut to fit cloth + resin? Hopefully someone's encountered this before!! Thanks for any advice!

Re: Big trouble.....
February 04, 2020 04:17PM
Outgassing caused the issue from what I have learned. The surface was assumedly fairly warm when the resin was applied. The residual heat in the substrate may have formed the bubbles you discovered.

The Gougeon Brothers on Boat Construction: Wood and WEST System Materials is a great resource for the use of epoxy in boat building. The best thing is it is a free download!

Rick Newman
Re: Big trouble.....
February 04, 2020 06:03PM
Thanks Rick I'll have to check it out. I have no doubts it was a temperature issue, as I had no trouble on the colder days with the same glass/resin set up on my plywood. Odd though that plascore would have held onto heat, but could be more "it's full of air and the air is hot" kinda thing. Thanks!

Brad
Re: Big trouble.....
February 04, 2020 06:16PM
Yes I concur with Rick: outgassing. Grind out the bubbles and patch in with glass strand. Then grind back to flat. Happened a boat or two back working with plywood and it all went well once back on track. Besides I can't see it from my house:-)

Check to make sure that your resin is all set before proceeding. 25 years ago I was fairing a nice little rowboat and although I used the correct amounts of resin vs hardener I had been distracted and failed to mix it before applying. What a mess. I had to use acetone thinner/grinding in combination in order to remove it and it continued to embarrass me long after.

Maybe it's just me but I don't seem to get along with the fast hardener.

Get back on that horse!
Re: Big trouble.....
February 04, 2020 09:27PM
I like to heat my shop thoroughly before starting so everything is the same temperature.

Then I turn the heat down so the layup happens in an ever so slightly cooling environment.

Then I do the layup and then babysit it on and off for three hours. If bubbles do appear I wet that area with a tad new resin and trowel it out with a 10" inch drywall knife.

What you've got is as ugly as I've seen. Yet still eminently fixable. You will have grind out the big ones.

Ouch. I don't really have an explanation
Re: Big trouble.....
February 04, 2020 09:39PM
Did you buy Plascore with or without the resin barrier?

I have never used anything but "with barrier"
Re: Big trouble.....
February 04, 2020 11:40PM
Uh Oh Sandy. Could you explain "resin Barrier? Sounds like something I'd get wrong........just my luck.
Re: Big trouble.....
February 05, 2020 03:03AM
I ordered with resin barrier. However I did have a hard time getting someone competent with plascore for a while, so it’s possible mistakes were made. The exterior of the plascore feels almost like felt? Not sure what it’s actually supposed to feel like. I agree with the bunch: fast set hardener, unexpectedly high temps, possibly a thin spot or two, puff goes the fiberglass. Most were domed up pretty high. Regardless the mission was to save it. I used a box cutter to remove all the loose domes and then hit everything with some 150 grit on my orbital sander. Ceramic paper. Went fast no fuss. Dipped troweled and laid out cloth patches with resin and seemed to go well. Will sand down where there’s some pools etc. as long as it doesn’t go vertical on me again should be good. Another layer over top some flow coats and some sanding and paint we can all pretend this never happened......right? I feel special I’ve even impressed Sandy with my goof!! May have been a blessing in disguise. Had some transom work I didn’t realize I needed to get some before I put the bottom on so finished that up tonight. Thanks for all the advice!!
Re: Big trouble.....
February 05, 2020 02:39PM
Some pics after bubbles cut out and post patching. Early returns show promise on the repair 12 hours later.



Re: Big trouble.....
February 05, 2020 06:53PM
:=))
Re: Big trouble.....
February 20, 2020 03:41PM
The bottom was going to get hammered anyway. Just cut them out, fill them and then add another layer of glass, no problem.

To those new to epoxy remember, as temps rise, air in plywood expands. Honeycomb has 100 times as much air in it. Shop temps should be stable or falling so that air does not expand.

Never glass a piece and place in the sun to fast cure it. Guess how I figured that one out.
Re: Big trouble.....
February 20, 2020 06:33PM
Working under that same theory. Just what we did. Cut them, filled them with patches, and will re-layer another section of cloth over the whole interior bottom. Gonna be fine. I've invested in some slower cure hardener in case the temps creep up again when it comes time to work on it. Unfortunately when I have time to work on it the weather is what it is - and in the deep south it's constantly swinging! Will look for falling. What I had was warmer than usual. But waited until night to get that falling temp, but suspect shop held on to temp longer and fast cure hardener created an exothermic reaction robust enough to float cloth!

Thanks for the expert advice, good to know goofs are a part of everyone's learning curve!
Re: Big trouble.....
February 20, 2020 07:43PM
Fast West System is not nearly as fast as RAKA's. So what fast means is subjective and relative.

I recommend slow for beginners. It's far more forgiving. Back in the early 1980s when I tried to build boats for sale I used West System Fast hardener. I made it work. I had to move quickly but I had the routine down and fast is good in the money context.

Trouble is I lost money anyway. When I realized it would be easier to write each new customer a $500 dollar check so I wouldn't actually have to build the boat, and so the money would work out the same, I closed up the shop. Actually I sold it and did quite well on the real estate transaction. Never did make a dime on any boats.

Now I build for fun. In slow motion. And I always use slow hardener. No matter who it's from. Also, fwiw, I only use epoxy for laminating glass. All wooden joints get glued together with Titebond III and a few clamps. Wood that doesn't have glass over top gets oiled, with tung oil and naptha.
Re: Big trouble.....
February 20, 2020 08:40PM
Might need to check into some titebond for wood to wood connections for my internal components. What's your ratio for tung oil to naptha? I was planning to use Deks for mine, but given it's basically that, would be interesting to do a cost comparison. Also read somewhere (here?) all tung oil isn't created equal? So would love to know your source/brand of tung.
Re: Big trouble.....
February 20, 2020 08:46PM
The last time I oiled wood (gunwales on a old Buffalo Boat) I bought a pint of tung oil downtown at the hardware store. Brand? What ever is there on the shelf. Then I mix it with naptha until it brushes on nicely. A new coat every day for three or four days.

I like to cook too. I never measure anything. I do well with curries stir fries and stews. BBQs pancakes and fish. But forget bread. You have to be precise to make good bread. Which filters me out of the equation.
Re: Big trouble.....
February 21, 2020 01:03PM
Bread:
3 cups of flour, 1 tablespoon of Gluten, 1 pack yeast, 1 tablespoon sugar, 1 teaspoon salt, 1+/- cup of water, 2 tablespoons of melted butter. Let rise in a greased bread pan, don't punch down, bake at 375 for 31 minutes.

Oil finish:
Make sure you read the msds sheet to be sure its Tung. The stuff some of the boxes sell under brand names is actually Soybean oil. You only need use the Naptha ( I use terpentine) on the first coat or two. then straight up. wipe of any excess 20 minutes after app or it won't dry very quickly.


Summary:
Homemade Bread is the perfect medium where one can consume heavenly amounts of fresh amish butter.
Re: Big trouble.....
March 02, 2020 04:13AM
Sandy, how do you keep the pancakes from dripping through the grill until they cook sufficiently?

Rick N
Re: Big trouble.....
March 02, 2020 11:24AM
On the river a flat aluminum grill on top of a Partner stove is hard to beat for breakfast. Dave Inskeep is a master.

Partner Stoves and grill pans. Pocatello Idaho. You can drive to Idaho, or buy one online through a dealer. Not cheap but they are the best.
Re: Big trouble.....
March 02, 2020 09:22PM
Looks like somethings you find in Smith and Edwards.
Re: Big trouble.....
March 07, 2020 03:44PM
They work well, especially when you need to feed a group, like on a trip down the Grand Canyon!

Rick N
Re: Big trouble.....
March 13, 2020 02:59PM
Sandy is right though...... They are pricey. I had never head of them before. Of course I have the Coleman green camp stove but they are slow to provide for a whole group of adults.
Sorry, only registered users may post in this forum.

Click here to login