I/O (Sterndrive) Conversion to Outboards

[tpenfield]

Another progress update . . .

I added a second layer of fiberglass (2415 stitchmat in this case) to the planing surface (upside down 'V' shaped portion, Joe).

Don't tell anybody, but I used plastic drop cloth to cover the surface after it was wet-out and pulled it tight in all areas to give the stitchmat a smoother surface. It also helps avoid dry spots . . .

I'll be putting a final layer of 1708 on the 'V' shape, and more glass of various types on the transom and sides.

It seems like I have lots of cloth, but not enough resin . . . I may need to get another pail of it. The resin I'm getting in the 5-gallon pails is 'Advanced Coatings 13886 MVP - No Wax'. I ran it by the resin Guru ( ondarvr ) and he thought it was pretty good.

 

[tpenfield]

Commentary . . .

I must say that doing a 'male-mold' approach is a lot slower than using a (female) mold as far as fiberglassing is concerned. Mostly because there is some amount of prep work (trimming, sanding, smoothing) before you can/should put the next layer on.

In a female mold (like the swim platform that I did back in 2019), you can just keep adding layers of glass without much prep work between layers.

Of course with this extension bracket, it would be difficult to make a female mold, given the funky geometry of it. The side panels have a reverse taper of about 1.5", so it would need to be done in half-molds that could be separated to release the 'part'.

Anyway, I digress . . .

 

[Pmt133]

I have what may be a dumb question... by using the drop cloth, does that act as a surface air inhibitor and allow the surface to fully cure? And if that's the case do you have to prep those areas between layups or is the unwaxed still good to go despite not being tacky?

 

[tpenfield]

I have what may be a dumb question... by using the drop cloth, does that act as a surface air inhibitor and allow the surface to fully cure? And if that's the case do you have to prep those areas between layups or is the unwaxed still good to go despite not being tacky?

Not a dumb question at all . . . Yes, it does allow the surface to cure to some extent. It sort of depends how long I keep the plastic on there and there are usually a few small air pockets that develop. I sand the surfaces between layers just to be sure of adhesion.

The Admiral noticed that the extension-bracket is starting to turn green.

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Yes, it is . . . the Advanced Coatings 13886 resin has a more green hue to it.

I'm into the second pail of resin. I used 140 oz. (1.09 gallons) yesterday and have the following pieces to layup today/tomorrow.

• Side panel forward sections (2) 1808: 46" x 20" + 22" x 9" triangular (54 oz total)
• Planing surface 1708: 91" x 50" (114 oz)
• Transom 1708: 68" x 40" (68 oz)

So, I'll use 236 oz (1.84 gallons) with these pieces., and I'll be about 3 gallons into the second pail. I'm going through resin a lot faster than anticipated, but if I back off on the amounts, I tend to get dry spots.

I can get another pail for about $250 locally.

I'll be ready to 'flip' the E-B back over later this week, which should ease Joe's distress. Then it is the splash wells and a few odds & ends . . . That's it.

It will be onto the boat modifications. Which will include a couple of stringers, a cross-brace, a flange grid, and some bracing into the existing stringers.
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In other news . . . My re-power guy told me one of the engines arrived last week and the second one is due this week. I may go see them later in the week.

 

[redneck joe]

Soooo... respectfully - you have your projected resin usage out to two decimal points. If your calculation are so precise what you gotta keep being more? Are you not calculating in loss for whatever reason and whatever name it is called in this instance?

 

[Pmt133]

The calculation just drifted a wee bit is all.

 

[tpenfield]

Soooo... respectfully - you have your projected resin usage out to two decimal points. If your calculation are so precise what you gotta keep being more? Are you not calculating in loss for whatever reason and whatever name it is called in this instance?

IDK . . . one of the world's mysteries. I think the latest batch of resin is not going as far as the previous. . . . I may have been a few gallons short of my estimates . . . not sure . . . In total, probably will use 10% more.

 

[tpenfield]

Speaking of resin and the need for sanding vs. not . . . Even with the plastic covering during curing, the resin still has some tackiness to it. I can tell with the sandpaper quickly clogging up.
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It is not a bad thing, because I am going through my 'old' supply of sandpaper that has been sitting around for a while.

A few weeks back, the Admiral got some porcelain tile for a (yet another) bathroom make-over. $500 later I was able to cut the tile.
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I also have a sanding wheel for it, and it makes quick work of roughing up the fiberglass surface for the next layer.

PPE is important with the angle grinder . . .

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It took only about 15 minutes to sand most of the outside surfaces in preparation for today's glassing.
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The new 'ankle' grinder will probably come in handy for the grinding needed in the boat itself.

 

[Pmt133]

If it helps, my fudge factor for resin was around 40%. I had 2 gallons left of the 35 I ordered. The last few layups it was getting a wee bit close for comfort.

All that said, some lay ups left a half inch of resin in the bottom of a quart mixing cup. There was probably close to 3 gallons of waste when you total all that up over the course of the project. That makes the actual fudge factor about 20% which is pretty standard for my sector.

 

[redneck joe]

In my world 20% was average unless i was running rhings thwn we were 10 to 12%.

 

[Scott Danforth]

in florida heat, I make smoking trophies...... a lot of smoking trophies..... Resin also solidifies in the pail without MEKP in the storage cabinet on really hot days.

 

[tpenfield]

in Florida heat, I make smoking trophies...... a lot of smoking trophies..... Resin also solidifies in the pail without MEKP in the storage cabinet on really hot days.

An ice bucket would be good for you . . .

 

[tpenfield]

If it helps, my fudge factor for resin was around 40%. I had 2 gallons left of the 35 I ordered. The last few layups it was getting a wee bit close for comfort.

All that said, some lay ups left a half inch of resin in the bottom of a quart mixing cup. There was probably close to 3 gallons of waste when you total all that up over the course of the project. That makes the actual fudge factor about 20% which is pretty standard for my sector.

Getting input from the Naval Engineer and the adjustments I made to the structure added about 4 gallons of resin and maybe 10 yds of cloth to my initial numbers. All for good though . . .

 

[Scott Danforth]

An ice bucket would be good for you . . .

I keep the beer in the ice bucket....