spraying gelcoat question

Discussion in 'Fiberglass and Composite Boat Building' started by CandR, Dec 8, 2008.

  1. CandR
    Joined: Dec 2008
    Posts: 3
    Likes: 0, Points: 1, Legacy Rep: 10
    Location: florida

    CandR New Member

    Hi,

    I have a quick question about spraying gelcoat using Duratec High Gloss additive.

    1. Do you catalyze ~2% vs gelcoat and then add duratec (1:1), or mix gelcoat with duratec and then catalyze with mekp on the total mixture amount?

    2. My gelcoat already has wax in it from the manufacturer. According the the data sheet on duratec, it says to mix and spray without wax, but then, if the repair is below the waterline, add wax? I'm confused. So, does it make no difference that my gelcoat has the wax already in it?

    3. What are folks using for small spray repair jobs? I have heard of Preval's, but is there anything else out there that works better?? I was told that I would need to spray, for fixing small dings in the gelcoat, so as not to get the "halo" effect. True???

    Thanks alot!

    Cheers,
    ted
     
  2. outkastoffshore
    Joined: Dec 2008
    Posts: 8
    Likes: 0, Points: 0, Legacy Rep: 10
    Location: st louis mo

    outkastoffshore Junior Member

    i use gelcoat mixed with patchaid the patchaid is a thiner and it make it go off faster and in about 15mins it is ready to sand and buff and its not tacky as far as % go i live in mo so we go by the temp and the best way to buff it is aqua buff 1000 and 2000 this is water based and will not burn the patch like old based i hope this help some how
     
  3. LMB
    Joined: Nov 2008
    Posts: 52
    Likes: 2, Points: 0, Legacy Rep: 37
    Location: North Carolina

    LMB Junior Member

    This is not as straight forward as it used to be, because most newer gel-coats are chemically different than a few years ago (MACT compliance removed most styrene). Duratec has a technical service so double check with them, but I think the wax will be a problem. I have used my share of Duratecs high gloss additive and it worked great, but I used it strictly in "traditional" (high solvent content) gel-coat that did not contain any wax. Even Duratec won't guarantee performance in low-voc gel-coats. You best bet with these is a fast patch-aid. A cheap siphon touch-up gun with at least a 1.5 to 2.0 needle/cap. Always catalyze the final ready to spray mixture at 2.0%
     
  4. CandR
    Joined: Dec 2008
    Posts: 3
    Likes: 0, Points: 1, Legacy Rep: 10
    Location: florida

    CandR New Member

    ok, thanks for the info, guys. I was also going to try the patchaid route as well side by side, to see which approach I liked better. I was just a little unsure about the duratec. I have had heard good things about it, hence, thought i'd give it a try. I tried to contact duratec by email, but got no where- i'll try calling them.
     
  5. carboncopy001
    Joined: Dec 2008
    Posts: 24
    Likes: 0, Points: 0, Legacy Rep: 10
    Location: vancouverisland, canada

    carboncopy001 Junior Member

    I have sprayed combinations of gel coats with duratec. With such as patch aid, acetone, styrene etc, and have had no problems. Mix together and catyalise 1% or 2% depends on how fast you need it to go off, remember you can always post cure. As I do repairs for a living, I look for the most efficent way to get it done. Also if you have to use a cheaper gun it aids in spraying gels through them. Have had many reps in the shop over the yrs and the one thing they will say is they dont know how it will act. Because they dont do this type of testing, if unsure do test samples first.

    Have fun
     
  6. carboncopy001
    Joined: Dec 2008
    Posts: 24
    Likes: 0, Points: 0, Legacy Rep: 10
    Location: vancouverisland, canada

    carboncopy001 Junior Member

    Mix and have fun, I do it with all my repairs. I have cut it 45% with gel and then thinned it out with with acetone and varrious thinners. Have tried patch aid and others and it is all about preferance. Also have had many reps through the shop including one of the former chemist from composite 1 and if they have not done this type of testing they won't have any answers. For the most part they dont do testing with other products. If unsure do test samples yourself, I also have seen it sprayed to extremes that I would not have done myself and works like a charm. So have fun, small repairs is a hard to say depends on what you are calling small.
     
  7. CandR
    Joined: Dec 2008
    Posts: 3
    Likes: 0, Points: 1, Legacy Rep: 10
    Location: florida

    CandR New Member

    carboncopy,

    Thanks for the info. I figured someone has probably done this before, so just looking for others experiences. I am a chemist, so I enjoy experimenting, and I will surely be doing test panels, before trying anything on the boat. As per small repairs, we're talking dings in the gelcoat, from dropping something on deck, etc.
     

  8. carboncopy001
    Joined: Dec 2008
    Posts: 24
    Likes: 0, Points: 0, Legacy Rep: 10
    Location: vancouverisland, canada

    carboncopy001 Junior Member

    Candr
    It is also not hard to do in the case of chips, you would zip them out with a dremel or if you have air a die grinder with a abraiding bit. I ussally take a 320 grit and give a light sand around the chip. Fill to the point of being proud or fill and tape over with masking tape. To prevent sagging in area's that have to much of a steep surface. The same applies to fractures (looks like a spider web or long cracks in gel coat )in both cases you need to check for damage beneath the repair. They will ussally appear whiteish this needs to be removed or your repair will fall out in due time or water will get behind your repair and begin delamination. Now in the case the repair goes deep in the material cab/resin fill works in small area's, mix to the consistancy of smooth peanut butter and it should still look wet. There are many ways to make different fills with gelcoat or resins it will all depend on the damage as to how to approach it.
     
Loading...
Similar Threads
  1. 236eagle
    Replies:
    19
    Views:
    12,024
  2. aaronhl
    Replies:
    7
    Views:
    260
  3. aaronhl
    Replies:
    12
    Views:
    2,998
  4. makonate
    Replies:
    7
    Views:
    7,201
  5. Bonefishr
    Replies:
    29
    Views:
    15,234
  6. dejavu89
    Replies:
    32
    Views:
    9,477
  7. jimflorida109
    Replies:
    6
    Views:
    6,403
  8. JackyJ243
    Replies:
    8
    Views:
    740
  9. Nachtvlinder
    Replies:
    2
    Views:
    301
  10. Scuff
    Replies:
    12
    Views:
    927
Forum posts represent the experience, opinion, and view of individual users. Boat Design Net does not necessarily endorse nor share the view of each individual post.
When making potentially dangerous or financial decisions, always employ and consult appropriate professionals. Your circumstances or experience may be different.