At the gelcoat stage - help needed!!!

[morebass 17]

Re: At the gelcoat stage - help needed!!!

7. Spray 1st coat with no additives, just acetone for thinning, amount of thinning will vary depending on the viscosity. I plan on a 10 mil thickness with each coat, and overall thickness of about 30 - 35 mil before any sanding.
8. Folowing day, spray another coat exactly the same as the last, with no additives.
9. Folowing day, spray my final coat with a wax additive that will be recomended by my resin supplier. Exact ratio still uncertain but in the region of about 10%.


All of these can be done in the same day back to back.

Gel coat needs to be sprayed about 18Mils or so for it to cure well, so two slightly thicker layers will be fine if you do them separately.

By the time you spray 18mils and clean the gun it will have gelled enough for you spray more over it without sagging, so you can do it all at one time if want.

Thats a much better way Ondarvr, I will go for two thicker coats then with the second coat containing wax.

How strict is the 18 mils though?, As I am basically a novice sprayer I don't think I will be able to achieve a uniform thickness throughout, also should all curves,corners be a little thicker as these will get hit harder on the sanding step?

 

[morebass 17]

Re: At the gelcoat stage - help needed!!!

Well I think I have ran out of questions, time to hit the books (this thread) and do my homework, so when it comes to spraying the gel I can do it blindfolded (not recomended unless you are Ondarvr or Yacht Dr. )

 

[morebass 17]

Re: At the gelcoat stage - help needed!!!

I want to get out and start sanding again but its 8am here and I don't think my neighbours would be too pleased with me. If only there was such a thing as a silent DA sander.
So while I am killing a bit of time here is a couple of pics of the parts I made from scratch for the interior, this is an example of my attempt at the roll & tip method.

TV surround : -
fibreglass stage,

filler stage : -

undercoat : -

painted : -

finished : -

temporarily in place : -

 

[morebass 17]

Re: At the gelcoat stage - help needed!!!

Here is a few pics of the helm console I made from scratch, knowing what i know now I can make this much better, but it will do me for the first season anyway.

new steering wheel

 

[morebass 17]

Re: At the gelcoat stage - help needed!!!

this is the rear hatch/woofer enclosure (hence the name "morebass" although my boat is actually a morbass 17' )

 

[morebass 17]

Re: At the gelcoat stage - help needed!!!

and here is my "battery distribution box" (patent pending) it also houses an inverter that will power the lcd screen and any other low power devices, and also contains the main fuses.

 

[morebass 17]

Re: At the gelcoat stage - help needed!!!

and finally ( I wont bore you nice people anymore with unrelated pics - promise )
here is the inside the way i left it before i flipped the hull, actually these were a while before the hull was flipped as almost all of the paint is now gone. just a little more sanding and a lick of paint, then I can put it all back together again and start work on the upholstery.

 

[morebass 17]

Re: At the gelcoat stage - help needed!!!

and here is the hull flip in progress, I welded a couple of brackets for the bow and transom and used a combination of an engine hoist, overhead gantry and a forklift. the gantry lifted the bow, the hoist lifted the transom and the forklift was used to control the spin. the reason I used the gantry for the bow and not another engine hoist was because this way I could pull the trailer straight out while the boat was getting spun in mid air. please note that a flip can be done with a lot less equipment but it meant it was a 1 man job and all of this was at my disposal so why not make it easy. The pics are not great as the flip took place in my work and I work nights so it was pitch black and i used a camera phone, but when I flip the hull back I will take better ones for anyone thats thinking of doing it.

 

[nymack66]

Re: At the gelcoat stage - help needed!!!

You have an excellent plan in my opinion; however here are the only things I do not agree on or it?s at lease debatable.

7. Spray 1st coat with no additives, just acetone for thinning, amount of thinning will vary depending on the viscosity. I plan on a 10 mil thickness with each coat, and overall thickness of about 30 - 35 mil before any sanding.

► I will recommend you use Styrene Monomer smells like crap however, I did during my restoration?
Here are the FACTS >> used as a thinner in gelcoats and resins to aid in application. Will not cause yellowing of gelcoat and is the preferred thinner/reducer to acetone when using with resins and gelcoats.
NOTE: Generally you should not thin resin or gelcoat more than 10%.

10. allow a 48 hour cure, then clean hull thoroughly with acetone again to remove most of the wax, now the fun part begins.

►Do not clean the Gel with Acetone at this stage, soap and water will suffice just fine. Acetone will compromise the integrity of the fresh Gel IMOH and from experience it seems to soften the Gel ?

11. start the sanding process with 320 - 400 and work my way up to 1200 - 1500. making sure I have removed all scratches from the previous grit.

►Step 11 is debatable in regards to the 1200-1500 stage I skip this step and used the diamond cut compound I mentioned (which is rated exactly within this grit) but it?s your call and I respect your judgment on this. I will hold to provide excellent results 

12. cutting/buffing stage. More research needed on this, but I will probably be using products from the 3M range.

►They have excellent products also.

Overall there will be 3 coats each aprox 10 mil, applied wet on dry with an overall thickness of about 30 - 35mil. At the moment I am thinking of using acetone for thinning but I may well change my mind.

►Excellent in my opinion of course ?35-40 Mils is the recommended thickness give or take, after a mirror shine you be looking at approximately 30-32 mils which and annual buffing going forward gives you 15-20 years plus of perfection? Please do not use the Acetone to thin you don?t have to?Good Luck and keep us posted?

 

[drewpster]

Re: At the gelcoat stage - help needed!!!

That Dist. panel is super nice. Very well thought out.

 

[morebass 17]

Re: At the gelcoat stage - help needed!!!

You have an excellent plan in my opinion; however here are the only things I do not agree on or it?s at lease debatable.

7. Spray 1st coat with no additives, just acetone for thinning, amount of thinning will vary depending on the viscosity. I plan on a 10 mil thickness with each coat, and overall thickness of about 30 - 35 mil before any sanding.

► I will recommend you use Styrene Monomer smells like crap however, I did during my restoration?
Here are the FACTS >> used as a thinner in gelcoats and resins to aid in application. Will not cause yellowing of gelcoat and is the preferred thinner/reducer to acetone when using with resins and gelcoats.
NOTE: Generally you should not thin resin or gelcoat more than 10%.

10. allow a 48 hour cure, then clean hull thoroughly with acetone again to remove most of the wax, now the fun part begins.

►Do not clean the Gel with Acetone at this stage, soap and water will suffice just fine. Acetone will compromise the integrity of the fresh Gel IMOH and from experience it seems to soften the Gel ?

11. start the sanding process with 320 - 400 and work my way up to 1200 - 1500. making sure I have removed all scratches from the previous grit.

►Step 11 is debatable in regards to the 1200-1500 stage I skip this step and used the diamond cut compound I mentioned (which is rated exactly within this grit) but it?s your call and I respect your judgment on this. I will hold to provide excellent results 

12. cutting/buffing stage. More research needed on this, but I will probably be using products from the 3M range.

►They have excellent products also.

Overall there will be 3 coats each aprox 10 mil, applied wet on dry with an overall thickness of about 30 - 35mil. At the moment I am thinking of using acetone for thinning but I may well change my mind.

►Excellent in my opinion of course ?35-40 Mils is the recommended thickness give or take, after a mirror shine you be looking at approximately 30-32 mils which and annual buffing going forward gives you 15-20 years plus of perfection? Please do not use the Acetone to thin you don?t have to?Good Luck and keep us posted?

Thanks nymack66, I am still looking into thinning & finishing products, however I think i will be taking your advice and use Styrene Monomer. It also makes sense not to clean with acetone, I will try soapy water first.

Regarding the thickness, 35 - 40 is better so i will aim for that, As ondarvr reecomended I am going with two coats instead of three. Each coat will be approx 18 mils and theoretically That will be 36 mils in total, However as I have next to no experience I probably wont get a uniform thickness throughout, So I might even aim for 38 - 40 to cover any low spots I might get.

I will not use acetone for thinning if I can help it, Thanks for the info nymack66 and the motivation boost. I will keep you all posted.

 

[morebass 17]

Re: At the gelcoat stage - help needed!!!

That Dist. panel is super nice. Very well thought out.

Thanks for the kind words drewpster.

 

[Yacht Dr.]

Re: At the gelcoat stage - help needed!!!

Hi morebass 17 sorry for the late reply ..

Ive only seen a boat rolled out one time. It didnt work out too good for the owner.

From what I understand at this point..

You have tacky uncured gel. You would wipe off that uncured surface with acetone. Just wipe away..keep wiping with more clean rags. ( Please wear a respo and some good gloves ).

This is how I full spray gel..

1. Get an el-cheapo Harbor Frieght 2 QT pressure pot ( NOT HVLP ).
2. Mix your gelcoat with 25ish % MEK Solvent ( Not the MEKP ) . Its kinda hard to tell how much you would thin because gelcoats are not All the same in viscosity. You want it kinda like tomato soup out of the can before you warm it up.
3. Have your surface all ready to go ( wiped down with acetone .. masked off etc. ).
4. Suit up good. Respo,suit,gloves,goggles with the holes taped up.
5. Have a box of powdered latex gloves, A few gals of acetone, cups , stir sticks, rags, a brush ( for clean up ).
6. Mix up your gel ( approx 10 CC per quart ).
7. put that in your pressure pot and start shooting away. Use side to side spray patterns. Release the trigger at the ends of the swipe. Basically you pull the trigger all the way back when you start your first motion...then release the trigger stopping the fluid ( keep the air still going just not the fluid )..then pull the trigger when coming back on your pass.
8. When you run out of gel.. open the pot up and put a few cups of acetone in there..flush it.
9. mix some more gel and do that over and over untill you have a good couple thick coats on there.
10. Clean your gun well with acetone. When flushing the gun you want to turn off the air leading to your GUN. you should only have a pee stream comeing from the tip of your gun when flushing ( You will need to have a "cheater" valve hooked to the bottom end of the gun itself for adjusting the air pressure to full off at the gun). Its hard to explain .. Ill take some pics of my gun setup so you know what im talking about.
11. wait untill the gel is tacky to the finger but does not pull off..then spray over the gelcoat with PVA (Polyvinyl alcohol).
12.let cure for a day. .. Rinse off with water and start your sanding steps ( Dry or wet-dry is does not matter ).
13.Buff out.

I would suggest that you play with your gun with water to kinda get used to it before you shoot . rinse out with acetone when your done playing around.

Oh..and after your done flushing the gun with acetone..before you spray your PVA .. Flush the gun with WATER !. Then spray your PVA..then flush it again with WATER...then final flush with acetone. PVA and acetone turns to SNOT .

The reason I never release the trigger all the way while spraying ( shutting down the fluid but not the air ) is because if a chunck gets jammed up in the needle while the air is off you will get a solid stream of gelcoat coming out..NOT good lol.

Its really not that hard..but its hard to explain in full detail with all the tricks and stuff..sorry..

Any questions just fire away..

YD.

I suggested MEK for thinning..not Styrene ( which Will yellow your gel..or acetone which could cause perosity ).

On full blown big boats we mixed styrene and acetone equal ratios till viscosity was sprayable. ( I dont know if that was right or wrong..but this guy seemed to know.. ) Pot life is needed.

So I really dont know were I went wrong on this how to step by step..could someone start shooting down some # steps please .

YD.

 

[morebass 17]

Re: At the gelcoat stage - help needed!!!

YD, I forgot you suggested MEK for thinning.
This is why I said that it was only a rough plan, and that I am going to reread this thread a few times as alot of info is supplied here and loads of it is from you and ondarvr, who I know have been there and done it many times so I am not dismissing your how to in any way, as i know your how to has been tried and tested and seceeded numerous times. its just at the moment there has been too much info to take it all in in one go. I will read over it a few times and let yous all know my final plan of action.
Regards
Ian

 

[ondarvr]

Re: At the gelcoat stage - help needed!!!

"FACTS >> used as a thinner in gelcoats and resins to aid in application. Will not cause yellowing of gelcoat and is the preferred thinner/reducer to acetone when using with resins and gelcoats.
NOTE: Generally you should not thin resin or gelcoat more than 10%."

Styrene is the main ingredient in gel coat that turns yellow, the more you add, the sooner it changes color and darker it gets. It also happens to be weak, brittle and less water resistant. I don?t dispute people use it frequently, and in small amounts its not bad, in fact small amounts of many things aren?t ?bad?, but people need to know what the side affects of these products are when used to make gel coat level and spray better.

Resin based products like Patchaid are what?s recommended.

 

[morebass 17]

Re: At the gelcoat stage - help needed!!!

YD. just re read your how to, and wth all the questions that have been answered since then and now that i have the spray equipment, it makes so much more sense now ( idiot proof )
The only thing i am unsure about is the following : -

2. Mix your gelcoat with 25ish % MEK Solvent ( Not the MEKP ) . Its kinda hard to tell how much you would thin because gelcoats are not All the same in viscosity. You want it kinda like tomato soup out of the can before you warm it up.

I know when you said 25ish % MEK Solvent that this was an estimate depending on the viscosity of the gel, and I know that we said that I may have to go above 10% but is 25ish not too much thinning or is it ok with MEK solvent. Sorry if the answer is staring me in the face. I am going to also do a bit of research on this MEK solvent stuff as i am unfamiliar with it.
Thanks again YD

 

[ondarvr]

Re: At the gelcoat stage - help needed!!!

In truth...... 25% of anything will have negative affects, if someone wants to live with them for easier
spraying that's up to them.

 

[morebass 17]

Re: At the gelcoat stage - help needed!!!

"FACTS >> used as a thinner in gelcoats and resins to aid in application. Will not cause yellowing of gelcoat and is the preferred thinner/reducer to acetone when using with resins and gelcoats.
NOTE: Generally you should not thin resin or gelcoat more than 10%."

Styrene is the main ingredient in gel coat that turns yellow, the more you add, the sooner it changes color and darker it gets. It also happens to be weak, brittle and less water resistant. I don?t dispute people use it frequently, and in small amounts its not bad, in fact small amounts of many things aren?t ?bad?, but people need to know what the side affects of these products are when used to make gel coat level and spray better.

Resin based products like Patchaid are what?s recommended.

Thanks Ondarvr for explaining that in detail.
The question I am left with now is

MEK solvent vs Patchaid?

Or is the results and quality very similar and its just down to the individuals preference?

 

[morebass 17]

Re: At the gelcoat stage - help needed!!!

Just had a look on my resin suppliers website, the only thing I see is the Styrene Monomer additive, and I know if i was to go in to the shop this is the product they would try to sell me, I will have a look and see if i can source MEK solvent or patchaid somewhere else. Here is link to my resin supplier if you are curious to what I am up against.

http://www.allscotltd.co.uk/SOLVENTS--ADDITIVES-&-SEALANTS/STYRENE/p-123-454/

I also just found some MEK solvent on ebay, here is the link for this.

http://cgi.ebay.co.uk/ws/eBayISAPI....akeTrack=true&ssPageName=VIP:watchlink:top:en

I still cant find a supplier of patchaid though, Is it maybe known as another name in the U.k. ?

 

[ondarvr]

Re: At the gelcoat stage - help needed!!!

Patchaid is far better. Patchaid is a trade marked name, but its also used to refer to products like it generically. The issue with this type of product is that it has a relatively short shelf life when compared to styrene or MEK, so suppliers don't like to keep it in stock, but some do have it. Check places that sell gel coat and ask them about patching products, they may have a different name for the products they supply.