How to fix glue blotches?

[ArthurB]

Hi,

 

I am new to staining and, after staining the stern on my current build - the Mayflower - there is some pretty noticeable blotching.  I am thinking this is from the CA glue I used to install the planks.  I am trying to be extra careful with the glue, but a bit had leaked through in those spots and I think I wiped it to get rid of the extra.  I thought I had sanded it enough prior to staining, but apparently not...

 

I did use the pre-stain wood conditioner and am using water-based stain: Minwax Colonial Walnut Wood-Sheen.

 

What would be the easiest way to fix this?  Sand it all right down to the raw wood again and then re-stain?  Or tear up the planks and re-do them, being more careful with the glue?

 

Also, what's the best way to ensure this doesn't happen when I start planking the rest of the hull (other than not wiping any excess glue away... )?

 

Thanks!

[S.Coleman]

I have not had this problem on my planks as I always use PVA glue for my planking. However on other parts of the ship where this has happened i have just sanded lightly over the area and restrained as I have done for my decking. Sometimes using a scraper carefully you can scrape that stain off.

[Keith_W]

I would like to hear the answer to this as well. The same problem afflicts my model. 

 

S.Coleman, the blotches that you see are areas where the stain has failed to stain the wood because of the glue. Even if you scrape off the glue post hoc, you will still be left with a lighter area. 

[ArthurB]

Thanks for the replies!

 

I went with giving the area a good sanding and then re-stained it.  It evened things out a much better.  It's still not perfect - it almost looks like the Patriots logo in the worst spot  - so I will probably go back and try again to clean it up. I've definitely learned my lesson and will be much more careful when gluing the rest of the planks on so I don't run into the same issue when staining the rest of the ship!

 

Arthur

[chris watton]

I think it is better to stain the planks before introducing them to even a sniff of glue.

 

Another alternative is to paint them 'wood colour' - there are so many good paints now that you can get a really excellent scale colour effect.

[ArthurB]

Good suggestion about the pre-staining, Chris.  I've actually done that with the stanchions I'm working on - I calculated how many full strips of wood I'll need to make all of the stanchions and stained them first so I don't make a mess trying to do it after attaching them.  Of course I'll need to re-do the tops once I've cut them to size and sanded them, but at least the rest of the lengths are all a consistent colour with no blotches.

 

I hadn't even thought of trying that for the main planking, tho, but it sounds like the way to go!  I'll post some pictures once I get to that phase, which will probably be in a week or two.

 

Thanks!

Arthur

[bogeygolpher]

The problem, as you are fully aware, is the glue gets down into the grain of the wood. Once the pores of the wood are clogged with glue, the stain will not be able to penetrate it.

 

You might get lucky and be able to get it off with sanding or using steel wool but if it really sunk into the wood you will have to resort to other methods.  You may be able to get rid of it using nail polish remover for the CA or water for PVA.  I use a Q-tip or cotton ball and apply a little at a time.  Dab it on and let it sit for a little bit, then try to remove the glue with a dry Q-tip or cotton ball. You may have to repeat this a number of times.

 

Another option is to use a gel stain.  Gel stains are almost the same as painting in that most of the stain sits on the surface rather than penetrate the wood.  It is much easier to get a uniform finish with them.

 

As to preventing it, I use PVA for my planking and use CA instead of clamps or pins as is suggested by Mastini in Ship Modeling Simplified. I put a very small drop of CA on the end of the plank, then a few inches of PVA on the plank, then using a sewing needle I place another very small drop of CA followed by another few inches of PVA, etc.  The CA holds the plank in place while the PVA cures and very little is required.  I also wipe the surface of each plank with water after applying it to make sure I have removed any excess glue.

 

However, as is obvious from my response, I too have shared the same malady as you and there is really no perfect resolution to the problem other than to try and minimize the occurrences and deal with them when it happens.

Edited October 4, 2013 by bogeygolpher

[Costas]

_{as others said, there is no miracle soution to the problem and we all , to a lesser or greater degree, face it}  

 

_{what I discovered is that acrylic stains (being water based) tend to not adhere to CA glues. It would be perhaps better (combined with other remedies you and others suggested) to use solvent based stains}

_{which have a much better adhereence (although that would not make the blotching disappear entirely).}

[Jaxboat]

I have become somewhat of an expert on this topic as my early efforts had real splotching issues. There are many great suggestions form the experts on our blog that I have tried. Here are the techniques I employ for preventing/correcting the issue:

 

Pre-staining/sealing definitely works. I have found that if you get a little white glue on the prestained/ sealed  plank it will peel off. Not so for CA but you can readilly remove using techniques described below

 

If you get white glue (PVA) on an unsealed plank apply IPOH (isopropol alcohol) on the splash as soon as possible with a Q tip (rub vigoorously). Use copious amount and follow up with a brisk rub with soft cloth before the spot dries. After the spot dries, sand. 

 

CA can be removed with nail polish remover (acetone). Use the q-tip method.

 

If a spot persists with either glue then scrape with a 22 blade (carefully!), retreat with appropriate solvent and resand.

 

 I also inspect the hull thoroughly before applying stain/ sealer to raw installed planking for spots that need treament. They generally show up as glossy spots on the unsealed wood. In fact, with a litte practice you can recognize CA spots versus PVA

 

 By using these techniques as well as immediately wiping any excess glue immediately it occurs, I have been able to greatly reduce glue splotches that have to be "post treated)

 

To summarize:

Use prestaining pre sealing as much as possible

Be neat when you glue.

If you do have a spot of excess glue, wipe away as soon as possible and apply appropriate solvent to the affected area using a q-tip to rub down spot, let dry and sand

Examine installed unstained/sealed wood (hull, deck, etc) before you apply finish and treat any glue spots. Lightly sand after treament

 

For persistent splotches use a 22 blade and scrape, reapply solvent let dry and sand

Best

Jaxboat

Edited November 22, 2013 by Jaxboat

[rwiederrich]

Really good question.......However, Most ships that were varnished then ended up gettingpainted anyway...it protected better and was typically the product on hand when refinish was necessary.  So I paint...since exposed wood was rarely seen on open water vessels..

 

Your example is very nice and a good modeling answer would be good.

 

Good luck and good model.

 

Rob