1987 Sea Sprite 225 SSB transom re build.

[Woodonglass]

Re: 1987 Sea Sprite 225 SSB transom re build.

Sorry, see below

 

[Woodonglass]

Re: 1987 Sea Sprite 225 SSB transom re build.

Just like stringers, they need to be bedded and tabbed. For Motor mounts I'd recommend using 4 layers of 1708. You need the added bulk for strength.

 

[Lwarden]

Re: 1987 Sea Sprite 225 SSB transom re build.

Heres a pic of the old mounts pre removal. How would you go about mounting the new ones? should I put some csm underneith them before I glue/pb them in? or just straight wood to fiberglass?

 

[Lwarden]

Re: 1987 Sea Sprite 225 SSB transom re build.

OK! got my transom filleted in and Im ready to begin my tabbing and lay up. Took some pics of my work but the pics dont show much. Ill add them to my photobucket if anyone cares to see. Here's a pic of my first attempt at making PB and using a zip lock freezer bag. Mixing it at the recommended 1% = 1 drop MEKP per Oz of resin.... lol! kicked before I could get it in the boat! lol!

 

[Lwarden]

Re: 1987 Sea Sprite 225 SSB transom re build.

 

[Woodonglass]

Re: 1987 Sea Sprite 225 SSB transom re build.

I think your mix ratio is way off. I'd recommend using the metric system and use CC's. Example 2 cups of resin = 16 oz. That's approx 480 CC's. 1% of 480 is 4.8 cc's. You can go to the drug store and find metric measuring cups and make your life a lot easier. Using a 1% ratio will give you a 15-20 minute work window with the peanut butter. Mix time should be about 1 minute after the hardener is added.

 

[Lwarden]

Re: 1987 Sea Sprite 225 SSB transom re build.

I think your mix ratio is way off. I'd recommend using the metric system and use CC's. Example 2 cups of resin = 16 oz. That's approx 480 CC's. 1% of 480 is 4.8 cc's. You can go to the drug store and find metric measuring cups and make your life a lot easier. Using a 1% ratio will give you a 15-20 minute work window with the peanut butter. Mix time should be about 1 minute after the hardener is added.

So with it being really warm here in mich should I go a little less than 1% to give myself a little more work time?

 

[jbcurt00]

Re: 1987 Sea Sprite 225 SSB transom re build.

You can, but it's less then ideal to use less then 1%.

How big are those drops to equal 1% of an ounce?

The attached PDF has the ratio for english units (using metric becomes much more accurate, 1% of 100ml is 1ml (1ml = 1cc))
View attachment MEKPRATIOCHART.pdf

Based on that chart, you almost HAVE to be using a higher % then 1% if the chart calls for 8drops of MEKP per ounce of resin.

Here's another reference that reflects the same ratio of 8drops per ounce:
View attachment MEKPChart.pdf

If you're using 1drop, and it's kicking to fast, the drop is way too big or there are other factors contributing to it's kick rate.

Are you working in the shade?

Has the boat been in the shade for several hours before you start working w/ the resin?

Are you storing the resin in a cool place until immediately before you mix it? Many use an old cooler to keep the resin chilled & in the garage.

How long are you mixing the resin?

Those 4 ^^^ can GREATLY impact how quick the resin kicks....

1st I'd try WOG's suggestion of metric, quick & easy to figure & measure accurately.

100ml resin/1ml MEKP
150ml/1.5ml
200ml/2ml
.
.
.
1000ml/10ml

You can see where that's going.

Mix small volumes in large containers. A quart of resin mixed in a quart container kicks VERY QUICKLY. The same quart mixed in a gallon container kicks slower.

The resin & everything you're putting it on needs to be cool or the warmth will speed the kick. Keep the fiberglass cloth in the shade too. Hot & humid are tough to overcome.

Mix for 30sec +/-. Any longer and you're using some of the small amount of workable time, as mix time.

 

[4Winns2]

Re: 1987 Sea Sprite 225 SSB transom re build.

Subscribed. Nice job.

 

[Woodonglass]

Re: 1987 Sea Sprite 225 SSB transom re build.

I never recommend going below 1%. I warm temps you can Fool the resin and catalyst by keeping them on ice in an ice chest and it will not kick as quick. I wouldn't mix more than 1000 cc at one time to avoid waste. Using 1/2 gallon ziploc bags would work best. You can even use Plastic Painters drop cloth and cut a 18" square, dump the PB in the center, fold up the corners, rubber band em and cut a hole that works too and cheaper!!!!

 

[Lwarden]

Re: 1987 Sea Sprite 225 SSB transom re build.

ok another silly question CSM> theres a hairy side and a more smooth side which goes to the wood? I'd assume hairy side but? and if Im only mixing qt's of resin at a time and its gonna take about 3qts per 2.84yrds of CSM to do my transom can I just keep mixing and working or do I need to let the finshed section tack up first?

 

[Woodonglass]

Re: 1987 Sea Sprite 225 SSB transom re build.

When doing large sections, I have my resin an catalyst pre mixed separately so I can dump the catalyst into the resin quickly and mix up another batch when needed. If I think I'll need 3 quarts then I pour 3 separate 1000 cc containers and 3 separate 10 cc containers of cat. Dump and mix when needed. No need to wait for the area to kick, just keep installing. Hair side down.

 

[saginawbayboater]

Re: 1987 Sea Sprite 225 SSB transom re build.

Lwarden this is US Composites program for Poly resin; notice above 90 degrees reduce MEKP by 50%

DIRECTIONS FOR POLYESTER HARDENER
POLYESTER RESIN/GELCOAT IS CATALYZED WITH MEKP (METHYL ETHYL KETONE PEROXIDE). THE RATIO IS APPROXIMATELY ONE
OUNCE OF HARDENER PER GALLON OF RESIN. USE THE FOLLOWING RATIOS FOR SMALLER AMOUNTS.
AMOUNT OF RESIN OR GELCOAT HARDENER AMOUNT
1 OUNCE 10 DROPS
1 PINT (16OZ) 1/8 OUNCE
1 QUART (32OZ) 1/4 OUNCE
1/2 GALLON (64OZ) 1/2 OUNCE
1 GALLON 1 OUNCE
THESE AMOUNTS ARE EASILY MEASURED IN THE OUNCE CUP WHICH IS SUPPLIED WITH THE RESIN. THE ABOVE RATIOS SHOULD GIVE YOU A
POT LIFE OF ABOUT 15 TO 20 MINUTES AT 80 DEGREES F. IF YOU ARE SATURATING FIBERGLASS REINFORCEMENT IT SHOULD BE READY TO
RECOAT IN ABOUT 1-1/2 HOURS. TIME WILL VARY FROM WINTER TO SUMMER SINCE HIGHER TEMPERATURES PRODUCE FASTER CURING. THE
RATIO OF HARDENER TO RESIN CAN BE INCREASED OR DECREASED BY 50% TO ADJUST FOR WEATHER, THICKNESS OR YOUR WORKING
PREFERENCE. TEMPERATURES ABOVE 90 DEGREES WILL DEFINITELY REQUIRE A 50% REDUCTION IN HARDENER AMOUNT.
TIPS: ALWAYS MIX THE MEKP INTO THE RESIN FOR AT LEAST 2 MINUTES, UNDERMIXING WILL RESULT IN UNCURED RESIN.
NEVER MIX QUANTITIES LESS THAN ONE OUNCE, EVEN IF YOU ONLY NEED ONE TEASPOON, MIX UP AT LEAST ONE OUNCE
LEAVING MIXED MATERIAL INSIDE YOUR CUP FOR EXTENDED TIME CAN RESULT IN A MUCH FASTER CURE. USE CAUTION
WHEN WORKING BELOW 60 DEGREES, ALWAYS TEST YOUR RESIN TO MAKE SURE YOU ARE GETTING A PROPER CURE.
PLEASE NOTE CAUTIONS ON BOTH THE HARDENER AND THE POLYESTER RESIN. MEKP IS A NASTY CHEMICAL AND YOU SHOULD AVOID GETTING
IT ON YOU. POLYESTER RESIN, GELCOAT AND SURFACING WAX ARE FLAMMABLE. SMOKING OR WORKING CLOSE TO A RUNNING ELECTRICAL
DEVICE OR AN OPEN FLAME SHOULD BE AVOIDED. GLOVES, FACE AND RESIPIRATORY PROTECTION SHOULD ALWAYS BE WORN.

 

[Lwarden]

Re: 1987 Sea Sprite 225 SSB transom re build.

Wow! I must say I love working with 1708 way better than 1.5oz CSM. So today I got a layer of CSM layed up on the transom and I got it tabbed in with the 1708, so tomorrow I'll continue with a layer of 1708 and finish with a layer of CSM. I'll post pics as soon as I get em downloaded. On a side note, my resin arrived today and in with the hardner was a half dozen little measuring cups with metric and cc graduations. So I think Im getting the hang of this fiberglassing...Thanks to alot of help from some very kind individuals...You guys here at Iboats are great...Thanks again...Lee

 

[Woodonglass]

Re: 1987 Sea Sprite 225 SSB transom re build.

If you need more you can buy em on Amazon. 100 of em cost $2 bucks. Or check with your local CVS or WalGreens. I get all my plastic mixing bowls from the Dollar Store or Dollar Tree. usually get 4 quart sized for a dollar.
Amazon.com: `Medicine Cups Disposable 1 oz. Graduated Pk/100: Health & Personal Care

 

[Lwarden]

Re: 1987 Sea Sprite 225 SSB transom re build.

OK! moving right along! transom is all layed up with 1 layer of 1.5oz CSM and 2 layers of 1708 and tabbed with 1708. Quite a nice job if I do say so myself. Wife wont come near me though, says I smell of plastic! Well hell yea when I've been playing in the stuff the last 3 days! So now its on to the stringers, one quick question, where my stringers attach to the transom, what's the best way to connect them? I do realize Ill be tabbing them to the transom, should I attach a cleat to screw them too or what? pic's tonight when I have time to upload them!

 

[Woodonglass]

Re: 1987 Sea Sprite 225 SSB transom re build.

Nah just use some 1708 to tab em to the Transom.

 

[Lwarden]

Re: 1987 Sea Sprite 225 SSB transom re build.

Saweeeet! thanks WOG!

 

[Lwarden]

Re: 1987 Sea Sprite 225 SSB transom re build.

Ok! Pics as promised!
1708 tabbing after 1 layer of 1.5oz CSM


After s layers of 1708 and installing the stringers.


Sistering them together

 

[Lwarden]

Re: 1987 Sea Sprite 225 SSB transom re build.

Smiling after a good hards days work!
[/URH
Hopefully tomorrow Ill get the stringers fileted in and tabbed and ready for glassing!