Question re: Arjay catalyzation guide before mix/pour

[CWKboat]

Hello, I am in the processing of preparing to mix and pour my transom with Arjay this weekend.

The local forecast is calling for a high of 93 degrees this Saturday afternoon when I plan to do the pour. Here is the Arjay catalyzation guide on their website:

http://www.arjaytech.com/products/CG/cg60.htm

The guide calls for mixing 129 grams per 5 gallon pail of Arjay at the anticipated daytime temps of 90-95 degrees. Being the American that I am, I am more readily familiar with ounces, so I converted the grams to ounces and the prescribed amount comes out to 4.55 ounces using this converter:

http://www.metric-conversions.org/weight/grams-to-ounces.htm

4.5 ounces seems like an awful small amount to mix with 5 gallons of Arjay, so I just wanted to make sure from the experts that I am on the right track, and have read and understood the catalyzation guide correctly?

I have a 1/2 inch 7 amp drill with joint compound mixing blade, so that's how I plan to mix it complete with chemical gloves, respirator, and safety goggles. Just want to verify that I have read the catalyzation guide correctly?

Thanks for verification.

 

[Coho Ghost]

Re: Question re: Arjay catalyzation guide before mix/pour

CW
Your gram to oz. conversion is correct. I've never done FG work at the temp you are working in, but that sounds about right for that temp. About 20 degrees above what I'm used to. Hopefully the experts will chime in with some REAL knowledge.

FWIW
Coho Ghost

 

[CWKboat]

Re: Question re: Arjay catalyzation guide before mix/pour

CW
Your gram to oz. conversion is correct. I've never done FG work at the temp you are working in, but that sounds about right for that temp. About 20 degrees above what I'm used to. Hopefully the experts will chime in with some REAL knowledge.

FWIW
Coho Ghost

Coho Ghost,

LOL, South Carolina Springs and early summers are very hot! Thanks for the confirmation, I'm hoping this goes well...

 

[GT1000000]

Re: Question re: Arjay catalyzation guide before mix/pour

According to all the calculators, 129 grams is equal to 4.55 ounces...1 ounce is approximately 29 grams...

You should stick with the recommended manufacturers specs, but seeing as the catalyzation table is variable to temps, that would indicate to me that this product will still cure even if you use a little less catalyst to give you more working time...

In other words, it is very much like Polyester resin, which can be catalyzed as little as .5% to as much as 3-4%, depending on temperature...the hotter it is the less you use, and vice versa...

Also keep in mind that catalysing a huge five gallon batch at one time creates a great deal more endothermic reaction than a smaller batch of say, 1 gallon...again, in other words, the more product you mix at one time the faster it will tend to catalyze/cure, due to the heat generated by the chemical reaction of a larger volume of product...

IMHO, you should be fine, according to the spec sheet of that particular product, to add just 4 ounces or even a little less, of the MEKP, which will give you a little bit longer working time...

The other thing to keep in mind, and this is very important...If you are working in direct sunlight, your heat index may be much higher than the ambient temp, by a considerable amount...If you forget to take this into account, your expected 93? temp may be as high as 100? or more, in which case the "kick-off" time of the Arjay may be a lot faster than you expect, and the stuff may start to harden on you prematurely...

If you are working in the shade, it should be about right...

Hope I didn't confuse or confound, but I am just trying to help using my own experience with catalyzed materials...

Best of luck,
GT1M

 

[Woodonglass]

Re: Question re: Arjay catalyzation guide before mix/pour

If at all possible you should do this in the shade, Not in direct sunlight. The mix ratio is correct and you'll have 20 minutes to get it poured in. You should have a "Poke Stick" ready to ensure the material gets into all the cracks and crevices and gets compacted well. A helper will be a great asset. Hopefully you have built a "Funnel" to help with pouring it into the transom void.

 

[Coho Ghost]

Re: Question re: Arjay catalyzation guide before mix/pour

CW,
Like GT said the pour will get quite hot. I did a NIDA transom in a a 70 degree garage, and the measured surface temp on the outer transom skin was 160-170F at max kick off. The poured transoms a a little spendy, but they sure work neat after all the prep is done.

Coho Ghost

 

[Coho Ghost]

Re: Question re: Arjay catalyzation guide before mix/pour

CW,

Something to consider, that I forgot to do when I poured my transom. Be sure the transom top is level port to starboard, and the rear face or the transom is plumb vertical. The pourable compound is runny enough that it collects at the lowest point out of square, and you'll end up with and area not filled clear to the top of the transom.

FWIW
Coho Ghost

 

[CWKboat]

Re: Question re: Arjay catalyzation guide before mix/pour

According to all the calculators, 129 grams is equal to 4.55 ounces...1 ounce is approximately 29 grams...

You should stick with the recommended manufacturers specs, but seeing as the catalyzation table is variable to temps, that would indicate to me that this product will still cure even if you use a little less catalyst to give you more working time...

In other words, it is very much like Polyester resin, which can be catalyzed as little as .5% to as much as 3-4%, depending on temperature...the hotter it is the less you use, and vice versa...

Also keep in mind that catalysing a huge five gallon batch at one time creates a great deal more endothermic reaction than a smaller batch of say, 1 gallon...again, in other words, the more product you mix at one time the faster it will tend to catalyze/cure, due to the heat generated by the chemical reaction of a larger volume of product...

IMHO, you should be fine, according to the spec sheet of that particular product, to add just 4 ounces or even a little less, of the MEKP, which will give you a little bit longer working time...

The other thing to keep in mind, and this is very important...If you are working in direct sunlight, your heat index may be much higher than the ambient temp, by a considerable amount...If you forget to take this into account, your expected 93? temp may be as high as 100? or more, in which case the "kick-off" time of the Arjay may be a lot faster than you expect, and the stuff may start to harden on you prematurely...

If you are working in the shade, it should be about right...

Hope I didn't confuse or confound, but I am just trying to help using my own experience with catalyzed materials...

Best of luck,
GT1M

Thanks for the very good info this helps tremendously with knowing how much wiggle room I have!

 

[CWKboat]

Re: Question re: Arjay catalyzation guide before mix/pour

If at all possible you should do this in the shade, Not in direct sunlight. The mix ratio is correct and you'll have 20 minutes to get it poured in. You should have a "Poke Stick" ready to ensure the material gets into all the cracks and crevices and gets compacted well. A helper will be a great asset. Hopefully you have built a "Funnel" to help with pouring it into the transom void.

Thanks WOG! Re: the funnel, I saw online where a guy had used a rubber road cone, so I was planning to use one myself unless I can come up with something better. I'll have a helper and will utilize the poke stick as you note.

PS. really enjoyed watching your upholstery videos as I'm also redoing the upholstery on this particular boat.

 

[CWKboat]

Re: Question re: Arjay catalyzation guide before mix/pour

CW,

Something to consider, that I forgot to do when I poured my transom. Be sure the transom top is level port to starboard, and the rear face or the transom is plumb vertical. The pourable compound is runny enough that it collects at the lowest point out of square, and you'll end up with and area not filled clear to the top of the transom.

FWIW
Coho Ghost

Hadn't thought of that! Mine has the "wings" on both sides of the motor mount area, so I'll be sealing off the middle area at the top and then up to the top of the wings, and then pouring from one of the high sides, so maybe that will somewhat alleviate what you describe. If it's winds up a little off at the top of the wings on either side, hopefully I can just fill it in as needed.

Great info, thanks for the help and helpful suggestions everyone!

 

[CWKboat]

Re: Question re: Arjay catalyzation guide before mix/pour

CW,
The poured transoms a a little spendy, but they sure work neat after all the prep is done.

Coho Ghost

Tell me about it, LOL. I bought two 5 gallon pails, and am really hoping that I don't have to order a third. It cost me about $115 to ship 2 pails and the MEKP from Fla to SC. This boat has a composite floor and foam stringers, so I didn't want to put any wood in the transom . So, I felt that the poured route was the way to go even if it's pricey. I'll have a rot proof boat with more structural integrity than when it was new.

 

[Coho Ghost]

Re: Question re: Arjay catalyzation guide before mix/pour

CW,
I live in Washington state, and had to pay $113.00 to have 6 gallons ( a 5 gal. + a 1 gal) shipped up here from Florida. The product only cost $132.00! NIDA is pretty good on the one gallon units - they are free you just pay the shipping. The i gals. are the over run from a run of 5 gal. units.

Coho Ghost

 

[CWKboat]

Re: Question re: Arjay catalyzation guide before mix/pour

CW,
I live in Washington state, and had to pay $113.00 to have 6 gallons ( a 5 gal. + a 1 gal) shipped up here from Florida. The product only cost $132.00! NIDA is pretty good on the one gallon units - they are free you just pay the shipping. The i gals. are the over run from a run of 5 gal. units.

Coho Ghost

The Arjay was $176 per 5 gallon pail, and I saw where the Nidabond is now listed as $155 per 5 gallon pail. I couldn't find anyone to sell me the Nida, so I went with Arjay although I guess it's essentially the same product.

What size boat did you use the 6 gallons on? I'm sure hoping I have enough to finsish it without ordering more.

 

[CarTuner]

Re: Question re: Arjay catalyzation guide before mix/pour

I used the Arjay/Nidabond products when redoing my stringers. They work great. I mixed less than the full 5 gallons at a time to give myself more working time and flexability. Also have a rubber mallet on hand to pound on the front/back of the transom to help get the air bubbles out.

 

[Coho Ghost]

Re: Question re: Arjay catalyzation guide before mix/pour

CK,

I'm not surprised the NIDA has gone up in price. I did mine in 2010. I actually ordered directly from NIDA, and did not try to find a local supplier.

Coho Ghost

 

[CWKboat]

Re: Question re: Arjay catalyzation guide before mix/pour

CK,

I'm not surprised the NIDA has gone up in price. I did mine in 2010. I actually ordered directly from NIDA, and did not try to find a local supplier.

Coho Ghost

Coho,

Question: When you poured, did you seal your holes with tape? I have the sides I also have to pour that are higher than center of the transom, so was planning to tightly tape all the way up the edges to the top on each side. I guess I'll have to hope for the best on that.

Also, I was planning on using some C-clamps and a 2 X4 across the outer skin and inner skin to reinforce the tape and keep the top of the skins at least from bowing outward due to hydraulic pressure. Did you have any bowing out at all, or did you reinforce the cavity at all? With the cost of this stuff, I just don't want to screw this up!

Thanks again for relating your experience with your pour!

 

[Coho Ghost]

Re: Question re: Arjay catalyzation guide before mix/pour

CK,
Yes I put duct tape over the holes, most of mine were pretty small. I didn't have any problem with the inner and outer skins wanting to bulge out. I don't think the hydrolic pressure is enough to be concerned about. I did however force a half dozen "cubes" of 35 lb density urethane
foam down in between the outer skin and inner skin of the transom to keep the pour space a consistent width. I think Seacast actually sells poly ester blocks this purpose. I also screwed a 60" piece of 1"x1"x1/8" steel angle to the transom face to pull some of the "bow" out of it from being void of the wood core. I can't remember which company Arjay, NIDA or Seacast shows on their website how to set up and pour the wings. You might check all three, there might be some helpful info there. The wing pour may have been done after the main transom kicked off to prevent leakage. I cheated and did not pour my wings. With the design of the transom and the amount of power I put on the boat it was a nonissue.

FWIW
Coho Ghost

 

[CWKboat]

Re: Question re: Arjay catalyzation guide before mix/pour

Hey guys,

One more quick question re: the MEKP: I ordered the Arjay from Fiberglass Coatings in Fla, and the Arjay site catalyzation guide is for Lupersol DDM-9, whereas I would up ordering MEKP-925 from Fiberglass Coating with the Arjay.

Are Lupersol DDM-9 and MEKP-925 going to have roughly the same properties and gel time? Not knowing much about the chemistry involved, it appears they are similar, but thought someone could shed some light maybe.

 

[Georgesalmon]

Re: Question re: Arjay catalyzation guide before mix/pour

Those two cat's are roughly the same and you won't have any trouble. They are both 9% active oxy.

 

[CWKboat]

Re: Question re: Arjay catalyzation guide before mix/pour

Those two cat's are roughly the same and you won't have any trouble. They are both 9% active oxy.

Good to know, thanks!